referencing C++.net Code from VB.net

[Bum]

Hello,

First off let me preface that I'm not a C programmer.

I have a solution that contains both C++ project and a vb project. I reference the C++ project in my vb project so I can use the C code in my vb. I create routines inside a class in C++, then build it. This works all well and good until I have a *variable in my routine, when I try to use the routine in my VB I get this error:

'MyRoutine' has a return type that is not supported or parameter types that are not supported.

here's the C code:

 
namespace MIX2C {

	unsigned long Class1::Session( char *MinAPILevel )
	{
		unsigned long Answer;
		Answer = 55;
		Answer = InitializeSession(MinAPILevel);
		return Answer;
	};
}

Here's the vb call:

        Dim cls As New MIX2C.Class1
        Dim BB As String = "Hello"
        Dim ans As UInteger = cls.Session(BB)
        txtresult.Text = ans

Any Ideas?

thanx!