"If I don't see you through the week, I'll see you through the window."

It's not exactly award winning stand-up but it was probably the most quoted line across the west of Scotland circa 1982.

And the rest of the script of Gregory's Girl, come to that, with time taken out to argue over whether we most want to be cool, blonde Dee Hepburn as Dorothy, the girl Gregory wanted, or dizzy loveable Claire Grogan, the girl he eventually got.

Gangly Gregory was our icon, Cumbernauld somewhat unfeasibily became a mecca. The year was 1982. Gregory's Girl was the first real cult Scottish film. I have friends to this day who can still quote the script line by line.

Nearly 20 years later, Bill Forsyth has returned to his best-known subject

Almost 20 years on, director Bill Forsyth has come up with a sequel. His intentions have been known around the Scottish film industry for well over a decade, but like most people he was well aware of the pitfalls of trying to follow-up such a hugely popular film.

"We were aware of the dangers of even contemplating recreating Gregory," he says.

"We didn't approach it as a sequel - not after all this years - but as another film with the same character. So we virtually started over again with a clean slate.

"We decided to eavesdrop on Gregory's life and to ask: where is he now? What is he up to? The original character was adolescent and awkward, almost in a pantomime way and we might have made the mistake of going overboard in trying to ingratiate the new character with the audience.

BBC Scotland Arts Correspondent Pauline McLean on Gregory's return

"We avoided that not least by the sheer acting instinct of John Gordon Sinclair. Having John play Gregory again was like an anchor - his persona would always give the character its integrity."

Sinclair said he was delighted to return to the role he first played as a gangly teenager. In Gregory's Two Girls, he plays a 35-year-old Gregory, now a teacher in his old school.

"I don't think I'm quite as gangly now," he says. "I've had to take gangling lessons for this film."

Minefield of crush on pupil

This time, instead of being torn between the football mad Dorothy and her quieter, wackier mate, he's divided between another teacher and one of his pupils. - a 16-year-old school pupil and a potential minefield for Forsyth.

He admits it's a far cry from the original but believes it's handled with delicacy. And Gregory's innocent approach helps.

"Because John is quite unique as an actor, he can walk the fine tightrope of the teacher having a crush on a pupil and at no stage do we condemn him because we can see how hard he's working to deal with his feelings for Frances. How he suffers as much as he gains pleasure from it."

John Gordon Sinclair attending Prince Edward's wedding, with Ruthie Henshall

Aside from John Gordon Sinclair, few of the original cast survive. But you will recognise a few of the locations. It's the same school because, of course, Gregory returned there as a teacher. Gregory meets his girl in the same place - under the tree in the park - although Forsyth says that was accidental.

"We went back to the park and looked for a tree to shoot the scene under," he says.

"It turned out to be the same tree from the first film - although we didn't intend it to be."

Gregory's Two Girls is the latest Scottish film to have an injection of Scottish Arts Council lottery money. Ironic, considering Forsyth's much publicised views on public financing of film.

"I still think lottery funding of film is a dubious business and I do have my doubts about how its' used," he says.

"But I think the way it is being handed out now has changed and it's beginning to be a better system. I also think ours will be one of the first films to actually give money back to the lottery fund so that's changed my mind a little."

So if it's a success, will it mark yet another return of Gregory, with or without his girls? "Oh no," groans John Gordon Sinclair.

"Twenty years later and Gregory is middle-aged and still gangling. I don't think I can face that ... mind you, I said that 18 years ago too ... and look what happened."

"Hmm," adds Bill Forsyth.