programming mercedes keys

Hi everyone I dropped my key and it broke apart and snapped the infrared sender off the front of the pcb :-( tried soldering it on and it was barely usable to put back on as the pins were gone, anyway i purchased some spare keys to swap the ir over from one of them and it still wont send a...

I have a Sept 2000 W220 with the normal three button remote key. I also have an identical looking three button key which I bought from a local none MB garage which is second hand, and I don't know which car it came from. Can it be re programmed to fit my car?