HELP! Concatentation of 2 INT columns in SQL 2000

I am looking to do a concatentation of 2 integer columns without converting them to varchar in SQL Server 2000. If you do a concatentation operator(+) on two integer columns it will try to do math instead of concatenation. Does anyone know how to do this without doing a cast or convert statement? I am asking due to performance issues.
Here is the statement that I am trying to change:

select
cast(a.so_id as varchar ) + cast(a.line as varchar) cust_db_shipment_key,
MULTIPLE OTHER PARTS OF THE STATEMENT

from SO_LINE a left join SO b on a.SO_ID = b.SO_ID where carrier_id = '2' and cast(a.so_id as varchar) + cast(a.line as varchar) = ?

Thanks for the help in advance!!!!!!!!
SteveThere isn't too much of a performance hit for doing this in the SELECT. That FROM will kill you though. I would make it:
SELECT
CAST(a.so_id AS VARCHAR) + CAST(a.line AS VARCHAR) AS cust_db_shipment_key,
blah,
blah,
blah
FROM
SO_LINE a
LEFT JOIN SO b ON a.SO_ID = b.SO_ID
WHERE
carrier_id = '2'
AND so_id = LEFT(@.whatever,2) --However the string is broken down.
AND a.line = RIGHT(@.whatever,2)|||OK...I have come to the conclusion that I will not be keeping the columns as int's. The (@.whatever, 2)...what is that representing?
Thanks,
Steve|||?? Whatever the "?" is in your post. I'm assuming your passing a string or something to this query aren't you?|||This works great so far. I am working off of a limited dataset so tomorrow will be the real test but so far so good.
Thanks again,
Steve