There’s this message in the standard edit control, EM_GetSel or for the RichEd, EM_EXGETSEL. Is there only a decl for GetSel() and no def?
Sounds good about the manifest, use mt.exe, or to “save” on extra files there’s also #pragma comment(linker,"\"/manifestdependency ... which would go nicely in one of the main headers e.g stdafx.h. Using the Windows common controls will restrict the compilation to running just Windows of course.