SSRS 2005 treenode as report parameter

Question

Hi,

I have report data that belongs to regions in a tree (with infinite levels). What I would want is to allow the user to choose a region (node in the tree), and pass that parameter on to my stored procedure, which will collect appropriate data.

I have created some reports with drill-down matrices, which sort of does what I want. I need to do this for any type of report, such as charts, though.

Is this possible with SSRS 2005? If so, what is the best way to achieve it? Do I need to create a custom .NET component?

Thanks.