Simulating with boosters

Newbie here, still working on my first rocket. I know nothing of simulators ... yet. My question is concerning simulations with boosters. My current project is a rocket about the size of Estes Super Big Bertha, 29 mm engine with BT-80 body, with two drop-away boosters, also 29 mm BT-60 bodies. A total of about 150 N-sec of thrust. It is about 90% completed. Can I simulate such a thing? All the simulations I have seen so far just include one engine.

Herschel