When using a Follow POP, is there anyway to get the distance from a particle to its leader. For example if I have 10 particles each traveling towards a leader and I want them to slow down before hitting the leader and eventually stop.

This would be easy be just typing a expression in the max speed in a Speed POP. If I only could get the distance from the particle to the goal/leader.

I've tried using the Proximity POP but haven't found a good solution for it.