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

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

    The relative position from the start of source-string to the
    first equal character or zero if no match is found.