How could you copy the contents of an HDC to a bitmap?
Off the top of my head I think you need to:
I'm at home so can't give you any code, so I hope this is enough to get you started. There is a good GDI section on Code Project.
http://www.codeproject.com/KB/graphics/
There is a good piece of sample code here that does just that (amongst other things).
I've used a similar technique before (many moons ago), but do not have the code to hand.