Sql server query

I need to insert zero in the field by using the select query.

my query is like as below......


SELECT AppID + '-' +
cast(CASE
WHEN len(Batchid)=6 then batchid
WHEN len(batchid)=4 THEN '0' +batchid
ELSE 4545
END as varchar(10))

FROM Xaction
WHERE (BatchID = '6191') AND (AppID = 'GPWHS')


but it is not putting the preceeding zeros. pl. suggest. it is urgent

Thanks
Regards

SELECT
right('0000000000'+rtrim(cast(numfieldname as char(10))),10) as numfieldname2
FROM tablename