Excel and Barcodes

Hello. I am currently setting up a pick and pack system for items using scanned barcodes. What I have is a source excel spreadsheet that lists a customer (by ID) and a list of items they are to receive that day / week / month, etc. What I need is a program that will allow me to scan a barcode into excel and have excel determine if that item is a match to one of the items that customer is scheduled to receive. If so, a quantity should update. If not, I need a warning sound. I could also use Access to hold table data but am not sure where to turn for the spreadsheet table setup or the scripting for the comparision, etc. Anybody have a good starting point?

The barcodes are all numeric in nature and are varying lengths. I wasn't sure what you meant by the "enter" reference. But, I would prefer the scan auto-enter so as to reduce any human interaction if that is what you meant. I believe, now, when I have scanned in inventory, I do require to hit the enter key to submit it to an Excel cell.