VS2012 package loading DGML file

Hello,

I have a project that constructs a DGML file.
Now i want to build a VS package that will be able to load the DGML file into a Toolbar

or

as a text editor window tab inside the VS UI (same as when to use File->Open File...) .

I've looked up a walkthrough for doing something with a mediaElement.

http://msdn.microsoft.com/en-us/library/cc138567.aspx

But i can't find a way to do it with DGML file.

Please help.

Alex