The ALICE-HMPID detector extends the PID capabilities in the central rapidity region of the ALICE central detectors (ITS, TPC, TOF), by identifying charged pions and kaons with momentum 1 < p < 3 GeV/c and protons 1.5 < p < 5 GeV/c . Because of the small geometrical acceptance of HMPID, an efficient trigger system could enrich the sample of good events for physics. In this work, a simulation study to select events by using the Fast-OR signal of the ALICE Silicon Pixel Detector (SPD) combined with the signal from the ALICE Time-Of-Flight detector will be presented.