Final Cut Express Serial with broken Mac

I bought Final Cut Express but lost the computer first (hard disc failure, not recoverable) and then my pack for the software with the serial. I do have a serial for Final Cut Express written down but it does not seam to work. Any idea what I can do?

PS I tried to contact Apple online but wasn't able to find any address where I can write my stuff to. I have a proof of purchase but whom can I ask? The support site looks like a labyrinth.

Message was edited by: AndreasLoeffler