Richedit hook filtering EM_SETTEXTEX?

[murlbrown]

I am using a class library built by michael kennedy that creates a
system wide hook on the WH_KEYBOARD_LL, but I wanted to changed it to
become a hook for a RichEdit box in another application.
I modified the class keeping a majority of his code, and built a
c#(.net) front end to use this c++ built core library, passing it the
hook type of EM_SETTEXTEX (WM_USER + 97) and the threadID of the
richedit box, his class comes up telling me that this type of hook has
not been implemented. The question/problem here is what includes and
any defines need to be included in the .cpp hook file to work for a
RichEdit box and could it be that I am using a wrong version of
RichEdit?
Has anyone dealt with this type of c++ RichEdit(EM_SETTEXTEX) hook?