[CMake] Two C Compilers

[John David Duncan]

Hi,

I'm looking at building a large project on Windows.  I am currently  
able to build the whole project using CMake and Visual Studio.

Now I'd like to add a "subproject" (or just a directory), but in this  
particular subdirectory the C language files need to be compiled with  
mingw (because of extensive use of C99).  I understand that, in  
theory, I should be able to compile these with mingw into DLLs and  
then link with the rest of the project.

I'd still like to control the whole build with CMake, but I see at  
least two potential problems.  One is that I can't override  
CMAKE_C_COMPILER, and another is that in the subproject I may need  
CMake to use a Makefile generator rather than a Visual Studio project  
generator.

Does anyone know if there's a way to do this with CMake?

Thanks,

JD