Use old Lego wireless transmitter with arduino?

Hi all

Since my girlfriend thinks i spend to much money on electronics (and I kind of agree :P), I am trying to reuse some goods I have laying around.
I am relatively new to microprocessors, but I have been playing around with arduino for a couple of months now and I am a second year student of electronics and eager to learn.
So, I am trying to find out if it would be possible to hook an arduino into the circuit on the pictures below (pictures will be posted below since I wasn't allowed to post them in my first post here on the forum) and send and receive serial transmissions. The circuit originates from a LEGO Cybermaster set and the base station is connected to a pc via a RS232 port.

Link to some info about LEGO Cybermaster:

Backside:

Frontside:

Anyone got any ideas?