You can define MSW in the project settings -> preprocessor defines dialog if you're using an IDE like Visual Studio. AFAIK the only function that _has_ to be exported is setup.
Martin
its compiled now, but the pd console says:
load_object: Symbol "partconv_tilde_setup" not found partconv~/partconv~: can't load library
even though the code definately has this:
__declspec(dllexport) void partconv_tilde_setup(void) { ...
pete.