How rotate a vector in blueprint ?

Hi Cleava, thanks for your help, I appreciate this.

This is what i want to do ! But if you change the cube rotation, the rays follows the cube ? This is my problem. If i change the rotation of my object, my rays are not sent correctly.

Please explain me how you did.

I heard that there is some raytracing included in the lights, is that true ? Can i use with others actors ?