Library /sys$common/syshlp/dtehelp.hlb SPAWN, Parameters  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 command-string
    Specifies a command string to be executed in the context of the
    created subprocess. When the command completes, the subprocess
    terminates and control is returned to the parent process. If you
    use both the /INPUT qualifier and a command string, commands are
    obtained from the input file after the specified command string
    executes. The command string cannot exceed 132 characters.