Code Coverage when testing c++ code using c#

Here's the situation:

I am writing unit tests in C# for C# code that calls functions written in C++/CLI which in turn call functions that are written in C++. The C++/CLI code and the C++ code are in a different solution than the one the C# code is in.

The unit test runs successfully.

However, it only supplied code coverage analysis for the C# module. The DLL for the C++/CLI code and it's PDB file are both in the same folder as the Unit testing DLL. (The C++ code does not have a DLL, it has a LIB file).

What should I do in order to get code coverage analysis for the C++/CLI and the C++ code?