physical force feedback

Hi I want to integrade the VR Unity with the exoskeleton in my Lab. One of the problem I'm having is extract the physical force from Unity. For example, when I shoot a gun, I want to be able to get the recoil force from the gun and apply it on the exoskeleton, so I feel like shooting a gun. An other example, when I pickup a box with the vive controller, I want to get the gravity force on the box so I can apply the force on the exo and make user feel like picking somthing up.

I'm very new to unity. Can anyone suggest what function or library I should look into? Thanks