Execute a named command file containing commands to #(NETREG_NAME).

     DO command file

 An alternate form if this command is:

     @command file

 The commands in the command file must appear as if entered at the
 "DECNET_REGISTER>" prompt.  A #(COMMAND_FILE) can reference other
 command files.

 Commands are processed in order until the end of the file or until a
 command error occurs.