Today I received a response from MetaQuotes Software Corp about my inquiry.
Their response:
MetaQuotes: "You can create DLL files in any high-level programming language."
Me: "Does this mean .Net DLLs as well?"
MetaQuotes: "Yes, you can. "

I asked for a sample but am not going to wait on it so I will attempt to make a C# DLL by myself. I will post the sample solution if I am successful.
This means a C++ wrapper is not necessary.