ethernet to usb bridge with existing project

I have a finished project (over a dozen units out in use) and the end user now wants to add tcp/ip control. Adding the needed chips and hardware to the project would be very difficult. The units are simply a keypad that drives a shift register LED display. Currently the only available IO is the on board FIDI USB chip. I have experimented with sending the digits via the USB and that will work fine. The question is can I use an Ethernet to USB bridge to accomplish the TCP/IP interface?