|Learn Charles Petzold "Windows Programing" by heart.
Next trawl thru the MFC samples.
Look at other peoples code.
The most difficult aspect to MFC is getting this Window from another window.
Some other Control (SOC)
Now take an example where you want to communicate to from SOC to any other element in the Windows app?
I will demonstrate this technique in an article I'm preparing, just for a note I ask the same question to Jeff Prosise at a Windows Development Conference an he could'nt give me the actual answer.
It's quite easy a simple map store at app level so you can get at any window with little indirection.