Hi,
It depends how you generated the rayCast, but that should not be difficult, you want to add a force at the hit point of contact, but I guess your problem is that you use RayCastFrom GameObject right?
in that case, getting the direction of the ray as a vector3, use the following action: TransformDirection
tell which local axis you are using ( 1,0,0 if you are firing on the positive x axis)
is that what you are after?
bye,
Jean