turning off the alarm on peugeot 106?

I have an old M reg'd Peugeot 106 with what i believe has a factory fitted alarm. When i got the car the alarm didn't seem to be working as i didn't get a 'plip' key with it. I've just changed the car battery and every time i connect it, the alarm activates 'quite annoying' and i can't turn it off. There does not seem to be any kind of isolator in the car or under the bonnett.
Any suggestions? can i disconnect it?
I can get a spare key from Peugeot but it would take 3 wks and £150.00

Keith
June 2007