zOs/SQL/XUP1

-- select MAX(DECIMAL(STRIP(WK009ID))) from A540769.TWK009A ;
insert into A540769.TWK009A (wk009id, wk009Txt)
    select char(MAX(DECIMAL(STRIP(WK009ID), 7))+1), 'mx1'
        from A540769.TWK009A ;
insert into A540769.TWK009A (wk009id, wk009Txt)
    select char(MAX(DECIMAL(STRIP(WK009ID), 7))+1), 'mx2'
        from A540769.TWK009A ;
insert into A540769.TWK009A (wk009id, wk009Txt)
    select char(MAX(DECIMAL(STRIP(WK009ID), 7))+1), 'mx3'
        from A540769.TWK009A ;

SELECT *            from A540769.TWK009A ;