Compiling Order Sheet from File

[Ants]

I have an inventory file that holds the details of products sold: item number, description, upc/barcode, retail price, wholesale price, etc. When a wholesale customer comes into the store, he picks out the items he wants and indicate to our sales associates how many pieces of each he wants. I would like to create a solution to scan in each upc/barcode to do a find in the present file, have the choice set into a portal, which would then pull up the price for the items via the relationship in the portal, and we can indicate how many pieces are desired. If the customer picks out 30 items, at the end of the session we would have a portal with 30 portal rows.

I have the general idea but do not know where to start. Any ideas, solutions and suggestions would be greatly appreciated.