Does anyone have firsthand experiences (and sources of information) on efficiently porting WIN32 applications to WIN CE5.0 intelligent devices(ARM)?

I have got a free VNC client software that has been developed for Windows, and its my assigment to make a WNCE5.0 port. Many header files are missing and i do not have the experience to know how to systematically work through the project to straighten out the differences (to omit some headerfiles like crtdbg.h or dbghelp.h, nt.h, windows.h - or to migrate to WIN CE5.0 counterparts (of which i do not know whether they exist)).

I am working with the WINCE5.0 SDK.