[CMake] Mapping configurations and include_external_msproject()

[nick at appletonaudio.com]

Hi,

I'm using CMake for a project which (on Windows) uses 
include_external_msproject() to import Visual Studio project files which 
were generated by another build system. These project files do not 
contain the usual "Debug" and "Release" configurations, but have a large 
set of configurations which map over a set of parameters. In my project, 
I would like to be able to say that my "Release" build corresponds to a 
"xxxx_yyy_release" variant of the sub-project. The old set of posts 
below appear to be asking for the same thing:

https://cmake.org/pipermail/cmake/2016-February/062762.html

Currently, I can't seem to find a way to do this. It looks like the 
MAP_IMPORTED_CONFIG_* variables are what I want, but it does not look 
like they work with include_external_msproject(). 
https://cmake.org/cmake/help/v3.9/prop_tgt/MAP_IMPORTED_CONFIG_CONFIG.html

Does anyone have any advice?

Thanks!

Nick