how to convert comma seperated data to diff format in sql

Thats actually not simple - SQL does not have a concept of an array!
However, you can convert it into a temporary table, and use that. This is a stored procedure which accepts a list of commas separated values and uses that as the IN parameter of a query - pretty much what you are trying to do.

Pass a list as a string parameter:
DECLARE @INSTR as VARCHAR(MAX)
SET @INSTR = '2,3,177,'
DECLARE @SEPERATOR as VARCHAR(1)
DECLARE @SP INT
DECLARE @VALUE VARCHAR(1000)
SET @SEPERATOR = ','
CREATE TABLE #tempTab (id int not null)
WHILE PATINDEX('%' + @SEPERATOR + '%', @INSTR ) <> 0
BEGIN
   SELECT  @SP = PATINDEX('%' + @SEPERATOR + '%',@INSTR)
   SELECT  @VALUE = LEFT(@INSTR , @SP - 1)
   SELECT  @INSTR = STUFF(@INSTR, 1, @SP, '')
   INSERT INTO #tempTab (id) VALUES (@VALUE)
END
SELECT * FROM myTable WHERE id IN (SELECT id FROM #tempTab)
DROP TABLE #tempTab