Hi Chris,
Neither Quik Reports for DOS nor Quik Reports for Windows will be able to create a drop-down field that you can use for runtime value lookups.
If you have Quik Reports for Windows, you can use the 'Browse' feature from the Insert Database field to see a list of the vendors (or whichever field you choose) that are in the database. This is about as close as you can get in looking up values from within QRW.