ATtiny85 receive data and resend

Hi Noobie to ATtiny I want a ATtiny85 to receive a rfid tag number (from a usb HID device, which posts into file in focus.) into a file on ATtiny85. Then add a 2 digit prefix to the tag number, and then send the combined figure to Excel.

Thinking I will need to set up file on micro and set focus, once data received then send out via usb? to PC. Each reader would have its own battery powered micro and insert a different prefix.

Does this sound feasible? Use Arduino IDE, anything similar that I can start with? Thnaks

Charles Harris