Frontend creation using C++ [closed]-Collection of common programming errors

You could pick any of interop options that .NET ecosystem provides:

Of course, you always have ‘classic’ interop options, like having TCP/IP client-server, but this is overkill if you just need to call into methods of another dll.

Yes, it is possible. You can create back-end C++ code with a front-end C# UI. But it’s better if you use C# only, as it will be easier to manage.