Inject Open XML into an Open PowerPoint Presentation

I'm looking for a way to inject PresentationML and/or DrawingML into an 开发者_如何学JAVAopen PowerPoint 2007/2010 presentation using the Open XML SDK or just System.IO.Packaging. There is an article on doing this with Word, but in that example it is using the Range.XML routine in Word's object model, which I cannot find an equivalant for in PowerPoint's object model.

The reason I'm looking to do this is if I have an item on it that the PowerPoint client does not support editing of but that Open XML does (and as a result, PowerPoint will display it). I want to set this myself via a managed-addin (VSTO) on the open presentation. An example would be the underline of text (not that I'm looking for this, but it is an example) - in PowerPoint, you cannot make the underline of text a picture <a:blip/>, but in Open XML you can.

Does anyone know how to do this?

I am using both OpenXML SDK 2 and the Object Model to process presentations. What I do, simplistic as it sounds, is to save the presentation, close it, perform all the XML modifications I need using OpenXML SDK, and then load the presentation back and continue with the Object Model.

Nope, according to Microsoft support: http://www.ureader.com/msg/10972430.aspx