Int B3 Fn 77  - Zipkey - Play Back Exit Key For Entry With Given Zipcode   [U]

   AH = 77h
   DX = zipcode region (0-999)
   CH = last two digits of zipcode (0-99)
   BX = 16-bit BIOS keycode for a defined ZIPKEY alternate exit key

Return: CF set on error
       AX destroyed
   CF clear if successful
       zipcode specification as defined by the BX keystroke is placed in
         keyboard buffer, as if the user had popped up ZIPKEY and exited
         by pressing the key specified by BX