scaffold_resource und acts_as_tree

Routing nested resources on Models with has_many is very
straightforward eg.
Project->Iteration->WorkItem

can be mapped with:

map.resources :projects do |projects|
    projects.resources :iterations do |iterations|
      iterations.resources :workItems
    end
end

resulting in pleasant urls like
http://localhost:3000/projects/1/iterations/3/workitems

- but how can you map resources with acts_as_tree and an arbitrary
nesting?!
eg.

Treenode->Treenode->Treenode->...

I'm trying to achieve convenient urls roughly like:
http://localhost:3000/treenodes/1/children3/schildren/4/children/7

Has anyone ever tried to map acts_as_tree ressources in a RESful
manner?!

Thx for any tips!
stf