There is nothing like that now. Normal DLL's don't have anything for that. You could divide the header files and Function Panel files into two with the same DLL as the source. The next version of CVI (6.0) will have the ability to build ActiveX Server DLLs which means you can put these multiple interfaces in your DLL as you do with VB. It will come out later on in Q3.
Best Regards,
Chris Matthews
Measurement Studio Support Manager