This wont help you?

SELECT *, CASE WHEN Row_no > 1 THEN

CONVERT(varchar, WO)+ CHAR(63 + Row_no)

ELSE CONVERT(varchar,WO) END FROM

(Select * ,

Row_Number() OVER (Partition BY WO ORDER BY WO) as Row_No

FROM #WO) #t1

Ohh sorry, Steve is right, thanks Steve. This should work for you Sunil! (Steve was using RD instead of WO)

SELECT WO, CASE WHEN RowCnt > 1 THEN

CONVERT(varchar, WO) + '(' + CHAR(96 + Row_no) + ') '

ELSE CONVERT(varchar, WO) END FROM

(Select * ,

Row_Number() OVER (Partition BY WO ORDER BY WO) as Row_No

FROM #WO) #t1

INNER JOIN (SELECT wo AS Wo1,COUNT(*) AS RowCnt FROM #wo GROUP BY WO) a

ON #t1.WO = a.wo1