Hello,
When you say POS Sales Transaction, are you using an APP (ISV) solution like LS Retail, Insight Works POS, etc..? Each of these solution will record a transaction against a POS customer. If not, are you trying to create a way to record a POS transaction and have them post into the Customer Ledger Entry? If yes, you can create a POS Customer, have done this in the past, called POS Customer, and use this Customer No. and post Sales Invoices against it. You can update actual addresses if you want but I am not sure you want that information.
Hope this helps.
Thanks,
Steve