Adding custom attributes to a treeview node

 Hi Folks, does anyone know how I can add custom attributes to a treenode in code behind?
I am handling the databind with data from the db and its all working nicely but I now want to add drag drop facility to the treeview.  In order to do this I need to add 3 custom attrributes to render out onto the browser but I cannot do this in the normal manner as the treeviewnode does not support the attribute property e.g. I was expecting to do the following e.Node.Attributes.Add("ondragenter")  in the TreeNodeDataBound event handler but it is not possible.
Oh and I have to do it here because i need to pass a parameter to one of the javascript methods!
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