UPC is always 1 23456 78901 2 format. Except on small packages like gum or certs/rolaids.

3 of 9 can be any size since it will code letters and numbers, virtually the entire set of keyboard characters.

It really doesn't matter, since the scanner will read both with no problem.

Best thing to do is "scan in" the item number into Access as the item number for that product. Or, if you're used to calling it a D-5, but the UPC is 2 34567 98764 2 you can set up a seperate field for the barcode. With 3 of 9, you could make the barcode say D-5.

If you're comfortable with Access, that is sure the least expensive way to go.