[SCA Command] Spawns a subprocess running the DCL command
   interpreter and suspends the editing session.

                                  NOTE

      This function is not available in DECwindows; any attempt to
      invoke it incurs an error.

   Format

     SPAWN   [command]

Additional information available:

Parameter

command
   Specifies a command line to be executed by the spawned subprocess.
   If you specify this parameter, the subprocess ends and LSE regains
   control upon completion of the command.