Function:   DTSETDATE( [<expN1>]|[<expC1>] ) --> string

Synopsis:   Sets a date to a defined date format

            [<expN1>]|[<expC1>] numeric or string value identifying
                                the wanted date format

            When using a numeric value, keep in mind that only the
            following values are correct:

                        1   =   AMERICAN
                        2   =   ANSI
                        3   =   BRITISH
                        4   =   FRENCH
                        5   =   GERMAN
                        6   =   ITALIAN
                        7   =   JAPAN
                        8   =   USA

            The string values have been pre-defined in the headerfile
            VERTEX.CH and may used as follows

                        _AMERICAN
                        _ANSI
                        _BRITISH
                        _FRENCH
                        _GERMAN
                        _ITALIAN
                        _JAPAN
                        _USA

            You may also define Your own dateformat however keep in mind
            that it should be somehow in the format:

                            dd:mm:yy    if century is set OFF
                    or      dd:mm:yyyy  if century is set ON

            The delimiters are being used the way You have defined them.

Notes:      If CENTURY is set ON and You post a dateformat showing no
            century information, the function will not post your date.
            The same goes if You set CENTRY OFF and want to post a
            dateformat which includes century information.

Returns:    the current dateformat if new dateformat was
            posted successfully,
            otherwise empty string