RobotStudio event

bind tcp to an external rotary axis

I'm programming an ABB IRB6700 robot with 7 axes that needs to pour aluminum into a shell. 

Axis 7 of the robot is a rotary type and moves that cup( And it's on the robot).

I am looking for an instruction or functions that allow me to make a movement similar to the RelTool. That way I could place my tool in the tip of the cup and move it as it rotates.

I don't know if I have explained myself correctly....