How does it work?...URGENT!!!

Ok,so I undrerstand that you use AfxRegisterClass to register a windowclass that is process specifik. When registring a class you can specifi which WindowProc to use and different styles and so on.......
But how are you suppose to use this with the Graphical editor?
I would like to use a MFC class as a custom control but how does the editor know which MFC object to tie to my newley registred windowclass?
Also I would appriciate an example if theres someone out there who has it......

/THANKS