Studying the Arduino, I have known and used, the Xbee devices. I wanted to ask you if is possible to create a bridge, using two Xbee devices, to link a device that uses the RS232 (9-pin) and a PC. I would like to make a kind of virtual cable.
That is easy!
You will need a MAX232 chip on each XBee module, also a 3V power supply for each module.
Once you have them wired up it will be the same as having a cable.
I've never seen one of the serial port XBee boards. But with those and 2 of the right kind of XBees (series 1), properly configured, wireless communication is easy.