[CMake] Newbie question - how to use multiple C++ compilers?

[Bennett Smith]

Hello,

I am trying to convert our current home-brew build system to use
cmake.  One issue we have is that some libraries are built using
Visual C++ 7.1 and other libraries and executables are built using
VIsual C++ 6.0. I would like to somehow indicate in each subdirectory
which version of the C++ compiler is required, perhaps in the
CMakeLists.txt file.  Is this possible?

Many thanks

-- Bennett