Keyfob wont work Cobra 7777?

Hi.

Keyfob is old and taty. SDuddenly stopped working today. Took to local garage, they open the keyfob, push lef-hand big button and red light flashes. They say battery is OK, and managed to get the zapper to give out a signal.
So maybe a fault with car. It has a gizmo in the dashboard that needs a pen-style thing poking onto it to mobilise the car (car goes into passive immobilised mode until i either lock and unlock again with zapper OR use the pen-key). Problem is that i have lost the pen-key thing.
Car stuck now......

Can anybody help please??

Thanks,
Andy