Line judge communication

[Tony.oe4]

I am line judging a college match for the first time soon. I have a question about communicating to the R1.

Situation: Opposing players go up of a joust. During the joust, I clearly see player R1 push the ball into the antenna. I know I waive my flag and point at the antenna. The question is if the R1 doesn't know who touched the ball last before the ball hit the antenna, how do I communicate that to the R1 if s/he asks for my help? Do I point to the to the opposite end line or my end line to indicate which team touched the ball last or do I just yell at the R1 which team touched last (just joking on this one). But seriously, how do I communicate which team the ball was out off of if the R1 asks for help?