Communicating with ActiveX with a GCC compiler
How do I reference and communciate with an ActiveX library from within my gcc compiled application?
Well, I've never actually tried it, but there is no reason you wouldn't be able to do this. You basically just need to have the interface definitions for the classes you need (might be able to get this from VS) and then make the appropriate calls.
The function CoCreateInstance is in Ole32.dll, so you could probably load the library, get the entrypoint, and then you just have to find the CLSIDs for creating the COM object you want, etc. As long as you are careful about only casting with QueryInterface, you should be just fine; COM was designed specifically to provide binary compatibility so that this would be possible.
the hardest part will be getting all the headers and such that you need.