15.64.24.1  INPUT   - Selects  the  input  file.  Once a file is selected,
TOPDRAWER looks for all commands in that file.  After the last command  in
the file, TOPDRAWER looks for more input in the current file.
(Default:TOPDRAWER.TOP)

                                  WARNING
     If  any  commands  follow  SET FILE INPUT, they will be executed
     before the commands in the input file.