Win XP Keyboard USB Wedge

I have the following circumstances:

XP Home on laptop, only USB ports

2 or more USB RFID stick readers plugged into USB hub then to laptop.

Reading into Excel. Works well, but all read into same column on spreadsheet.

XP wont allow identifying each reader

I want to add a prefix or suffix to code going into Excel that shows the number of the USB device that did the read.

What is recommended answer ?