I want to ask question about how to call VB.NET DLL from C++ program
I have tried many times to call VB.NET DLL file from C++ and it is working fine but the problem
You can't directly access .NET code from native C++, you will need C++/CLI for that.
If your program needs to be native C++, there is the possibility of writing a mixed-mode wrapper DLL which provides a native C++ interface for the main program, and uses C++/CLI in the implementation to forward calls to the .NET DLL.