SET(OUTPUT_FILE)
  Specifies the output file for a buffer.  On exiting, if the buffer has
  been modified and is not set to no-write, DECTPU writes out the buffer
  using the output file specification.
  Syntax
     SET (OUTPUT_FILE, buffer, string)
  Parameters
     buffer     The buffer for which you want to set an output file
                specification.
     string     The output file specification for the buffer.  By default,
                the output file specification is the same as the input file
                specification (if any), with a version number one greater.
  Example
  The following statements set the output file specification for the paste
  buffer to LATEST_CUTS.TXT and write out the paste buffer to that file:
     SET (OUTPUT_FILE, paste_buffer, "latest_cuts.txt");
     WRITE_FILE (paste_buffer);
  Related topics
     EXIT              QUIT          SET(MODIFIABLE)
     SET(NO_WRITE)     SET(SYSTEM)   WRITE_FILE