Building MFC extension problem

[Wenrich]

I've finished a socket application and am trying to build the core part of the application into a DLL. the "core part" includes CMySocket class derived from CAsyncSocket, and some other helper classes. CMySocket stores a pointer to a CMainFrame object, which has proper functions that handle events occuring on the socket. The main purpose of writing this DLL is to make the CMySocket class easy to be reused for future applications. I want to define the handler function prototypes that the future applications would follow. I don't want to restrict the pointer to a CMainFrame object, rather it can be pointing to any CWnd-like object, which would allow more flexibility. My question is: since CMySocket needs a pointer to a CWnd to call proper handlers when events occuer, how can I get rid of the implementation of the functions and hence the CWnd-like class? (I don't think deriving a class from CWnd is a good idea; if so, that means the applications need to derived another new class from that one. Is it?) This is the first i ever try to build a DLL. Any hint is strongely welcome. (btw, the DLL would be an MFC extention DLL) Thank you so much! Wenrich