The Visual C++ 6.0 examples can be found in the /samples/vc/ directory.
Both the dispatch interface and the dual interface are showcased in this sample application. There is once again only one method demonstrated: ConvertToEuro - however, for both dispatch and dual interface, detailed code for error handling is given.
Use the following procedure to create the dispatch wrapper object:
The main file to investigate is mfccontrollerdlg.cpp.