right can anyone help as i am drawing a blank on this.

I am creating a reference database which basically allows the end user to scan (using a usb barcode scanner) a barcode into a cell on excel. Once this barcode is entered the sheet then does various look ups to display data.

Basically what i what to do is only allow entry of barcodes into one cell -
So I have locked all other cells so data entry is not possible but at present every time you enter a barcode with the scanner it automatically drops down to the cell below to enter the next number.

Ideally i would like the barcode scanner to keep entering barcodes to the same cell over writting previous scanned barcodes

help!!!