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

 command-string

    Specifies a command string of fewer than 132 characters that
    you want executed in the context of the created subprocess.
    When the command completes execution, the subprocess terminates
    and control returns to the parent process. If you specify both
    a command string and the /INPUT qualifier, the command string
    executes before additional commands are obtained from the /INPUT
    qualifier.