Hi,
Are you sure you need IK for this? Unity already has limb IK for its characters, I would suggest using that instead.
else, can you describe your character rig, and what you are missing? normally you don't need any custom actions, you just apply an impulse force to the hand using regular physics and you should be good to good, if you are not using physics, then you can actually control the hand movement using a tween and move locally the hand on its negative forward axis.
Bye,
Jean
