The following code illustrates how to determine the storage system.

   PSZ pszFileName;
   MMIOINFO mmioinfo;
   FOURCC fccStorageSystem;
   ULONG rc;
    ...

   memset( &mmioinfo, '\0', sizeof(MMIOINFO) );
   mmioinfo.fccIOProc = FOURCC_BND;
   strcpy( pszFileName, "myfile.bnd+element.foo" );

   rc = mmioIdentifyStorageSystem( pszFileName,
                                   &mmioinfo,
                                   &fccStorageSystem);
   if (rc)
     /* error */
   else
      {
      if (!fccStorageSystem)
         {
         return (MMIO_ERROR);
         }
      else
         {
         mmioinfo.fccChildIOProc = fccStorageSystem;
         }
      }
   ...