how to write 'P-code file' (from simulink) in m.file (for GUI)? within pushbutton callback

i want to develop a GUI with my simulink model. in my GUI design, the user need to insert the input value. then GUI need to calculate the the input value given by the user. the calculation can be achieve by using P-code. so how to call the P-code file in m.file within pushbutton callback?