Thanks for your reply.
I’ve done some more shopping and hope that this time the card will work. I’ve bought this one now:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=230413426813&ssPageName=STRK:MEWNX:IT
And I’ve bought a PCI to mini-PCI adapter and antenna cables.
This will be delivered from China, so it will take a while before I can report back if that that works…