Adding nodes to a tree component

[cpigg]

I have a tree like this:
root
-child
-childchild
-childchild
-child
-childchild
-childchild
I need to add a fresh node to the root and have it show up as a child with the root folder. I also need to add a child to the child and have it do the same thing. I first initially load the tree up with a xml file to first populate the tree. I couldn't find any documentation on this. If someone could help I would appreciate it!