Thanks Achim, aparently a new Wireless Access Point can be 100-300 bucks so it may be a while before we experiment with getting one.
If there is someplace you can plug it in, you could maybe buy a long enough network cable and run that to the nearest Switch/Hub/Router or whatever. That should be cheap enough.
Okay everybody it is official. It just is not going to work. I have had proffesionals in the field looking at this for two days now and if they can't do it no one can. It's basically down to a compatibility issue and until we get a new Wireless Access Point they are certain nothing can be done. Thanks for all of your help anyway, I feel I learnt a lot in this thread.