Set Model Callbacks with Simulink Block

Hey Guys

i want to set Model Callbacks of my Simulink Model with a Simulink bock. I want to make a body-Collision Library. To check for Body Collision, i use the InitFcn and StopFcn to detect body collision. If its possible i want to add a block to my library that automatically sets the InitFcn and StopFcn if i place it in a Simulink model.