Query Help - possible VBA solution? Array?

Hello Experts,

I need help with an Access query that checks a 'Business_Name' field in a table with approximately 1.3m records, against a table of about 300 corporate identifier codes.  
My query provides results, but they are not complete.  I've included both tables (unjoined) and I'm using an InStr function to get these results.  I have a feeling there is a solution for this but that it will involve VBA, which I am NOT proficient in!

I've provide my SQL below.  FYI -  [business_name_tx] is in table "T_UCVI" and  [Code] is in table "T_BusinessCodes"

My current SQL:  
SELECT DISTINCTROW T_UCVI.ID, T_UCVI.BUSINESS_NAME_TX, InStr(1,[business_name_tx],([code])) AS Corp1, InStr(2,[business_name_tx],(" " & [code])) AS Corp2
FROM T_BusinessCodes, T_UCVI
GROUP BY T_UCVI.ID, T_UCVI.BUSINESS_NAME_TX, InStr(1,[business_name_tx],([code])), InStr(2,[business_name_tx],(" " & [code]))
HAVING (((InStr(1,[business_name_tx],([code])))=1)) OR (((InStr(2,[business_name_tx],(" " & [code])))>1))
ORDER BY T_UCVI.BUSINESS_NAME_TX;

Thanks for all help!