Remote wont open the doors.

[datart]

I have had my 95 530 touring parked up for a few months whilst trying to sell it and hence the battery had gone flat.
I have recharged it but the the remote key wont unlock the doors.
If I unlock it manually the alarm goes off.

I have taken the batteries out of the remote to check them and they seem ok.

I have one of those keys with 2 buttons on it.A round one to lock it and a squarer one underneath to open it.

Have I reset the key by taking out the batteries? If so what can I do about it and more importantly how can I disarm the alarm so I can start the damn car.

I have seem some posts about reprogramming the key by removing the chip but I cant see anything in my key that is removeable.
Does anybody have a picture of what it looks like.

thanks in advance