i need to 'combine' two separate product files into 1 value list showing product_code, product_description fields which are in both files.

any help appreciated.

I hate seeing a question with no replies. It usually means we're all stumped. My obvious suggestion would be to combine the product files into one file. Make a field for "category," and you'll always be able to distinguish your "File A" products from the "File B." But I'm sure you have a ******* good reason for why you can't do that!

What exactly does the value list need to contain (in other words, what info must the field contain)?

If you're looking to combine records from two different files into one list, then Fitch's solution (combining the files) is basically it. If you need to differentiate between the two groups of products, add a field in the combined file to do so.