VMS Help RTL Routines, LIB$, LIB$SPANC, Returns  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    OpenVMS usage:cond_value
    type:         longword (unsigned)
    access:       write only
    mechanism:    by value

    The relative position in the source string of the character that
    terminated the operation is returned if such a character is
    found. Otherwise, zero is returned. If the source string has a
    zero length, then a zero is returned.