UPDATE rptledger r,(SELECT xxx.objid,xxx.controlno,@row:=IF(@prev=xxx.controlno,@row,0) + 1 AS rownum,@prev:=xxx.controlno
FROM
(SELECT r.objid,r.controlno FROM remittance r
INNER JOIN (SELECT objid,controlno, COUNT(controlno) AS c FROM remittance GROUP BY controlno HAVING c > 1)xx ON xx.controlno = r.controlno

ORDER BY xx.controlno)xxx
ORDER BY xxx.controlno,xxx.objid)xxxx
SET r.controlno = CONCAT(r.controlno,"-",xxxx.rownum)
WHERE r.objid = xxxx.objid;