VMS Help DTM, SPAWN, Command Qualifiers, /INPUT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

   /INPUT=file-specification

   Specifies an input file containing one or more commands for the
   spawned subprocess to execute. If you specify a command with an
   input file, the command is processed before the commands in the
   input file. The subprocess terminates when processing is complete.
   You cannot use wildcards in the file specification.