Well, not to that calibre, since I'm not professional, but I know the theory behind doing something like that. But if I could show you an example, it could help. Hold on..
Hey Vibs, how bout you send me one of your scans, and I'll colour it and show you what I can do. PM me and I'll send you my email address. That way you could tell if you like what I would be able to do in the way of colouring your drawings. ^__^
Edit:
This picture gives a good example of the editing I've done on line drawings. I do draw quite alot, actually, but this particular guy was drawn by my friend. The left side is a photograph she took of her drawing, and on the right is what I did with it. He's a little pizelly, but I could fix it.