i think your teacher is asking a lot of you, and if he does know the software then he is def asking a lot and giving an impossible task unless you were taught how to code source code. and if he does not know the software then he is a bad teacher for asking someone to do something that he himself knows nothing about.
i think he wants you to sort his game making problems out for him (clever man)
it would have to be coded in source code, as its a physics matter, and the physics for light reflection of a forever moving active bullit would need more than a script or get around, as i think with exams and all they want a proper moving correct and accurate reflective angle shooting lazer, which is not available on x9 or x10. to my knowledge anyway
but kravenwolfs idea works but it is a cheat i think and not a real reflective shot ( maybe im wrong ) also you cant move the gun i believe either ,i may be wrong on that too, but teachers are known to want to know how it was done, and it may pass or may not pass. so i suggest you get a plan b too.
can get mirrors and guns on tgc store which is on your x10 editor interface.
well done kravenwolf
an unquenchable thirst for knowledge of game creation!!!