Here is a link to the reference regarding RadTreeNode's client-side API: http://www.telerik.com/help/aspnet-ajax/tree_clientradtreenode.html
You can use node.set_expanded(true) in order to expand a node and node.set_selected(true) to select a node.
Here is a reference to the server-side instances of RadTreeNode: http://www.telerik.com/help/aspnet-ajax/telerik.web.ui-telerik.web.ui.radtreenode_members.html
You can use ExpandParentNodes
Hope this is helpful for you!
the Telerik team
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Public Issue Tracking
system and vote to affect the priority of the items