Maya:how move ball with hand movement

[sheikhoo]

i have two model and i want animate ball with hand movement
this is my model

i want when change Rotate Z of hand the ball Translate Y change
like this

i can use Outliner like this it's work for one human but i want move ball to another human in animation,can i change the ball in Outliner At the time of Animation?

[faux]

Set up a parent constraint between both targets and animate the constraint weight.

This is often called space switching