The following code illustrates how to obtain the module handle of an IOProc's DLL.
HMODULE hmodIOProc; ULONG rc; ... rc = mmioQueryIOProcModuleHandle((PMMIOPROC)&MyIOProc, &hmodIOProc) if (rc) /* error */ else ...The following is a procedure prototype for a standard I/O procedure call.
LONG APIENTRY MMIOPROC (PVOID pmmioinfo, USHORT usMsg, LONG lParam1, LONG lParam2);