how to replace an USB cord between computer and 3d printer with xbee ?

i own two xbee pro serie 1 and i would use them to replace a USB-A to USB-B cord between computer and 3d printer

i use two USB adapters
tests done

note : computer and 3d printer connected with USB cord works fine

1°) two xbee connected to XCTU , i test each direction transmission looping Tx to Rx :test ok

2°) one side xbee tied on computer to 3D program printer , the other side xbee connected to
terminal XCTU,i can see command from 3d program (repetier ,cura…) displayed > test ok

3°) REPETIER program > computer > usb cord > xbee xbee > usb cord > 3d printer no work at

4°) it seems there is no handshacking on side between printer and its xbee

5°) what i want and can’t find is how to get a totaly transparent connection

An idea ? please tell me it …