Sorry if this sounds rude, 'cos I don't mean to be, but could your friend be thinking of the advert for the (ex?) chocolate bar '54321'? It also had a song with it, that I'm ashamed to say I remember the words to (I have a half-minute attention span - adverts are all I can remember)!
Or maybe (s)he's thinking of a show which had some kind of countdown as part of it, and that's the main bit she remembers?
Sorry, no help at all, I'm sure - good luck!!
x