Problem:

173 Error calling a VB DLL

Resolution:

VB6 DLLs are actually COM DLLs.

You should not use the CALL statement to call then. You should use the COM Support in Net Express.

The Distributed Computing section of the help details the syntax requirements.

In summary you need a class-control section with something like:-

   mycomclass is "$OLE$theVBprogid"

and then use the INVOKE verb to call the COM methods.