Finding name of dll using C++ filename containing native C++ function

Finding name of dll using C++ filename containing native C++ function

I have a native C++ function which I wish to import into my C# project file.
I can see the C++ file containing this function and from there I can see
its folder location (absolute and relative path).
To import this function I need to specify the name of the dll which
contains this file. How do I get the name of this dll?
PS: the file is vcclr.h and its present in Visual Studio 9.0/VC/include
folder.