Tracking Numbers for Returns / RMA

Client is into retail business. Their sales reps who are in the field create a return order via their handheld device and then physically ship the items back to their warehouse. At the time of the shipment, they key-in the tracking nos. of the packages against the return order. The current legacy application creates an return/RMA order after receiving the file from their handheld device via integration and it also stores the tracking nos. of the packages that were sent by the sales rep. (There can be 3-4 packages or tracking nos.) Later on they use the return order no.