How do you get to Broadway? Well, you can practice until the cows come home, but in the case of Nan Knighton -- who wrote the book and lyrics for The Scarlet Pimpernel -- it helps to have the show's composer go to bat for you.

"In 1989, I had been writing for 20 years -- industrial shows, songs for the Radio City Music Hall Christmas show, that kind of thing -- but still had not gotten my foot in the door. Then Frank Wildhorn, who is a great believer in taking risks on unknowns, saw my lyrics and loved them and was able to convince the producers to take a chance on me," said Knighton in a chat with Playbill On-Line during the final weeks of Broadway previews.

Initially she was signed on as the lyricist -- and she and Wildhorn promptly scored a success with "You Are My Home," a Pimpernel song that became a hit single. Then in 1993, Knighton was asked to write the show's book as well. Thus began a second, more intensive period of research into the period of the French Revolution -- and a much more detailed reading of the original Scarlet Pimpernel, the early-1900s novel by Baroness Orczy.

"After my research, I decided to set the musical in 1794 -- not in 1792 like Baroness Orczy had done -- because it was the actual time of the Reign of Terror, the most bloodthirsty, terrifying moment in the Revolution when things had really gotten out of control and literally hundreds of people were being killed per day," said Knighton.

One of the the historical characters who figures into the plot of the musical is Robespierre, who in 1794 was the head henchman of the French Revolution -- although ironically, he himself was about to be denounced and guillotined. The interesting thing about Robespierre, says Knighton, is that he was responsible for the deaths of so many people but in fact "he was a very neurotic man who couldn't stand the sight of blood." The show's three principal characters -- Percy (Douglas Sills), a foppish gentleman who is secretly rescuing victims of the French Revolution; his wife, Marguerite (Christine Andreas); and his sworn enemy, Chauvelin (Terrence Mann) -- are fictional, so Knighton felt no qualms about "heightening their relationships" to make the romantic triangle more full bodied for the Broadway stage.

Thus in Knighton's libretto, Marguerite, who is an actress -- "which in 1794 was not your conventional choice of a career for a woman," says Knighton with a laugh -- is now a more active participant in the action; Percy has been turned into a "genuinely funny guy" rather than the exaggerated fop of the novel; and Chauvelin, who in Baroness Orczy's book is fairly one-dimensional, has been transformed from a man obsessed with catching the Scarlet Pimpernel into a "sexy, compelling character" who had carried on a rather tempestuous love affair with Marguerite in 1789, when the two had stormed the Bastille together, says Knighton.

"Marguerite has become unhappy in her marriage to Percy and Chauvelin is therefore hitting her in a very vulnerable time in her life," Knighton says -- and one suddenly realizes that this sword and dagger musical is not all that different from The Bridges of Madison County or any other contemporary love story.

As for Pimpernel's most famous (not to mention most parodied) bit of verse -- "We seek him here, we seek him there/Those Frenchies seek him everywhere/Is he in heaven? Is he in hell?/That demmed, elusive Pimpernel" -- it has been turned into a song that Percy teaches to the partygoers in the ballroom scene at the top of Act II.

"This allows everyone to have fun with all kinds of additional little bridges and verses such as 'He gives the Frenchies nothing but frustration. Think me he's a spoilsport. Each and every demmed decapitation he cuts short,' " says the lyricist.

Knighton's least favorite part of the creative process was making cuts in the show, but three weeks into rehearsals she bravely "took scissors in hand and cut out every bit of fat." (The show is now 25 minutes leaner.)

Unfortunately, in the trimming process Robespierre (David Cromwell) lost some of his lines, and the two comic female characters, Lady Digby (Sandy Rosenberg) and Lady Llewellyn (Pamela Burrell), were forced to bid adieu to some of their funnier moments.

"Every time I see those two ladies, I just want to fall down at their feet and say 'I'm sorry! I'm sorry!' " Knighton says. "I had to cut a lot of humorous and colorful lines because they simply weren't important to the story. And in this show, the story is central -- and everything else has to be sacrificed to telling that story."

Knighton, who was born in Baltimore, first wrote and directed plays under the tutelage of Wilford Leach, who taught her theatre class at Sarah Lawrence College. She received a master's degree in literature from Boston University, where her professors included the novelist John Barth and the poet Anne Sexton ("who taught me an enormous amount about finding your own voice and using fresh, unusual imagery"), and then landed a gig as a staff writer on a PBS show called "Consumer Survival Kit."

The job included writing dramatic sketches and song lyrics on a different topic each week -- such as dental care -- and from the start Knighton was hooked on the lyric-writing part: "It was like a light bulb went off in my head," she recalls today.

By this time -- the late-70s -- Knighton was married and the mother of two young children (who are today 18 and 26). She remembers writing music "at 3 AM, after everyone else was in bed.

"I'd have no composer or music, just these tunes in my head. It was like I was sitting and writing lyrics in a vacuum," Knighton says.

"There were years when I thought, What am I doing, sitting here night after night and writing these song lyrics and books that are just going to sit on the shelf and get dusty?

"As it turns out, none of the time I spent writing lyrics for fictitious musicals was wasted. When Scarlet Pimpernel came along, I was ready," she contends.

After the show opens on Nov. 9, Knighton will resume work on the West End musical Saturday Night Fever, for which she is adapting the screenplay. (It is scheduled to open in May 1998.) Also in the works is a musicalization of Lorna Doone with Wildhorn -- which the lyricist describes as a "show within a show" about a troupe of actors attempting to mount a production of the romantic adventure.

So how does it feel to be on the brink of success at long last?

"I'm at an age where I don't take myself quite so seriously," says Knighton. "I couldn't have handled any of this in my 20s."