GH Developer: Moving other grasshopper objects

Hello! As part of Sheepdog, I am trying to add a way in which the objects that lie within the outline of the Fence are moved with it if a key (e.g. W for now, to be finally decided) is pressed while the fence is dragged.

I have tried to implement this by updating the Pivot of those objects but that doesn’t seem to work. Is this possible at all? What is the correct way to do this?

Thanks,
Pablo