Has anyone managed to hook into the content tree and insert additional nodes where the user has a starting node set? To give you an example of what I'm trying to achieve:

We have a large site with five main site sections, dealing with different aspects of the company. Some of the users are locked down to just their section. We also have a "Settings" node under the root, that's shared across all sections. If the user has root content access, they can see the extra content node, but for the ones locked down, they don't get the settings node as it's above their starting node.

What I'm trying to do is insert the settings node into the tree, but I'm struggling to get it to work. If I hook into BeforeTreeRender, I can't seem to get to the methods I need to add extra items to the tree (the problem is creating an XmlTreeNode, it has no constructor and the method for returning one requires a reference to the tree class that I can't seem to get at from anywhere).

Do any of the Tree ninjas out there have any ideas how I can do this? I COULD write a custom content tree, but that breaks a bunch of stuff in the back office (mostly to do with permissions).

Any pointers hugely appreciated!

:)