C++

	in .h:

		typedef BOOL (__cdecl TOptionsFunction)(HWND hwndParent);
	in .cpp:
		extern "C" __declspec(dllexport) BOOL Options(HWND hwndParent)

C# ??

        public bool Options(IWin32Window hwndParent)


(my app complains that it can't find the "Options" function)