can i add a PIR detector to my accenta 8 mini alarm system?

Hi there, i have an accenta 8 mini alarm system installed, and i have just figured out how to set it etc. however the sensor on the front door must have been cut off when a new door was put on before i bought the house. I was wondering if i could just put a pir detector facing the front door to act as the entrance/exit detector. if so how do i do that.