SQL question

Hi, I'm using online 5.07 and I have a little problem here. I need to submit a query like this: select * from tabA where tabA.colX||tabA.colY=(select max(tabB.colX||tabB.coly) from tabB where ....) Since colX and colY are integers it doesn't work quite well. Is there a function that you can apply to those integers to pad them with zeroes? Sorry but I wouldn't ask to the list and I would read the manual if I had a 5.07 version manual. It seems like I have a 5.07 Online version and a 5.00 version manual. If such a function does not exist. How could I rewrite that SQL statement? I've tried select * from tabA where tabA.colX=(select max(tabB.colX) where ...) and tabA.colY=(select max(tabB.colY) where tabB.colX=tabA.colX and ...) but it didn't work.