I took your question to mean that you _only_ had VC++ 6.00 as a development
tool and wanted to get some interoperability without the upgrade in
development tool. So, I sketched your options in the free tools world.

Just by the way, what I sketched does not involve declaring managed classes
in unmanaged code as in #1.

Yes, you certainly can treat a .Net assembly as a COM component in maanged
code. In the book "Essential Guide to Managed Extensions for C++ (Apress)
Challa and Laksberg offer a few options.

I'm a little busy now, but if no one provides some snippets you can use a
proof of concept, I'll post them here later tonight.

Regards,
Will

I am happy to report that it works as doc'd. :-)

With VS.Net 2003 I created this toy class in C#

using System;
using System.Runtime.InteropServices;

namespace ClassLibrary1
{
[ClassInterface(ClassInterfaceType.AutoDual)]
public class Class1
{
 public Class1()
 {
 }

 public void SayHello()
 {
  Console.WriteLine("C# says hello!");
 }
}
}

Note that if your class doesn't have a dual interface you'll need to talk to
it via IDispatch. Yuck!

Then I registered the assembly and created a type library from it with the
command

   regasm /tlb:ClassLibrary1Lib.tlb ClassLibrary1.dll

With VC++ 6.0 I created this toy application which used the compiler's
import facility to read the type library and create the wrapper.

#include <windows.h>
#import "mscorlib.tlb" raw_interfaces_only

using namespace mscorlib;
#import "ClassLibrary1Lib.tlb"
using namespace ClassLibrary1;

int main()
{
CoInitialize(0);

_Class1Ptr class1(__uuidof(Class1));

class1->SayHello();

CoUninitialize();
return 0;
}

I put the C# assembly in the same directory as the executable and ran it. C#
speaks.

Regards,
Will