Get PDSElement from PDEElement or PDEContainer

Does anyone have advice on how to translate from the PDFEdit layer to the PDSEdit layer?

I'm writing a plugin for Acrobat Pro to help with accessibility programming but have run into a problem: I have a selection server where a user can select a PDEElement/PDEContainer on a page, but I cannot find a method to retreive the associated PDSElement from the structure tree using the selected PDEElement or Container.

I can go from the PDSElement to a PDEElement, but have not found a way to go in the opposite direction. Any tips?