executeable

I'm quickly trying to make a 1 off mod for minecraft but its very difficult since there is barely any documentation. What I'm trying to do is simply teleport the animal an item swings at to player spawn. I thought this would be rather simple. I went through the tutorials and created the item, but I can't find anything about detecting a swing and teleporting. I assume these are two very simple things. Would be much appreciated if someone helps me out.