Dear Tom,
the only way how to do that in the current version of the simulator is by averaging over several simulations, where you define/create new user locations for each run. You could also try to define your own walking model where you let the users jump to a random position after a fixed number of TTIs, but I am not sure if the extra effort outweighs simply performing several simulations with new user locations. (Also then you couldn’t change the number of UEs during one simulation).
Best regards,
Martin