The index command controls a VCR's on-screen display. VCR devices recognize this command.
wsprintf(lpstrCommand, "index %s %s %s", lpszDeviceID, lpszIndex, 
    lpszFlags); 
 | off | Turns off the on-screen display. | 
| on | Turns on the on-screen display. The item to be displayed is specified by the "index" flag of the set command. | 
Returns zero if successful or an error otherwise.
  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
MCI Overview, MCI Command Strings, set