NAME
        CreateRexxMsg - Create an ARexx message structure

    SYNOPSIS
        rexxmsg = CreateRexxMsg(port, extension, host)
        D0,A0                   A0    A1         D0

        struct rexxmsg *createrexxmsg(struct msgport *, ubyte *, ubyte *);

    FUNCTION
        This functions allocates an ARexx message packet.  The rexxmsg
        consists of a standard EXEC message structure extended to include
        the ARexx specific information.

    INPUTS
        port - A pointer to a public or private message port.  This *MUST*
               be a valid port as this is where the message will be replied.

        extension - A pointer to a NULL terminated string that is to be used
                    as the default extension for the REXX scripts.  If this
                    is NULL, the default is "REXX"

        host - A pointer to a NULL terminated string that is to be used
               as the default host port.  The name must be the same as the
               name of the public message port that is to be the default host.
               If this field is NULL, the default is REXX.

    RESULTS
        rexxmsg - A rexxmsg structure

    NOTES
        The extension and host strings must remain valid for as long as the
        rexxmsg exists as only the pointer to those strings are stored.

    SEE ALSO
        deleterexxmsg(), clearrexxmsg(), fillrexxmsg()

    BUGS