Most of the post on the internet about interoperability is the other way around (Calling C++ from C#) since C# is apparently the superior language in terms of developer friendliness. But a part of research work is to make weird combinations of system work regardless of the reason.
I succeeded in doing just that thank to this Visual C++ example (documentation is available in part 1 of the tutorial).
One thing to add is, I needed a tool to export .NET 4.0 to .tlb files so I can use the same assemblies in C++ (pure C++ and not C++.NET). The tool is called tlbgen, and the syntax is quite simple: