Have you got anything other than just the number as a starting point?
Might help if you can narrow it down any further - eg - do you know which country it's most likely from or even which decade? What it's made from?
Where is the serial no - eg - under bb & if so where specifically - or say on fork crown or one of rear stays?
Are there any other markings or logos under bb or anywhere else?
Have you got any photos, inc whole bike + details of lugs, bridges, seat stay caps or anything at all that looks distinctive?