Wrtining a COM DLL in either VC6 or 7

I have an application that was written in VC6 with MFC support.  It consists of a .exe user interface dialog and two dialog app DLL's that get called from the .exe that runs under NT4.0.  I now have to port the app. to 2000 and replace the VC++ .exe user interface with a VB .NET front end.  Since the original .exe passes data structures to the DLL's I wanted to replace this functionality of passing data structure parameters functionality by compiling the DLL's as type libraries so the VB .NET front end could call the functions as if they exist in the VB .NET app.  This is done by adding a reference to the VB project and it works fine using VB6.  When moving to the VB .NET environment however the DLL's it appears have to be COM compliant DLL's in order to be Added as a reference to the VB .NET project.
I don't have the foggiest idea how to create a COM DLL as there is no option in the DLL wizard that includes COM support in VC6 and I have no real experience with VC7 to know if it is a built for DLL's.