Copying/Moving 2 parent/child nodes between 2 different trees?

[Mark]

So I have 2 trees, one pulls data that consists of parent and child nodes and another that has the same. What I want to do is to allow a user to drag and/or double click on a node, whether it be a child or a parent and add that to the other treeview. If though an action is done to move a child node from one tree to another and the same parent exists in both, then that child node, whether user drags and drops or double clicks will automatically route to the correct parent node. This way, a user couldn't accidently move a child node into the wrong parent node. I really hope this makes sense as I have tried several things to no avail and had assumed that this would be more straight forward. 

Thanks much.