Find coordinates of shapes on a visio diagram

I need a way to programatically find the coordinates of shapes on a visio diagram. The shapes themselves are easy to identify, as they all have a uni开发者_如何学编程que name. The only information i need is the absolute coordinates of the shape on the visio diagram. Ive looked through the output of both the vdx and svg save options, but i cant make sense of any of the coordinate information it outputs. Any ideas?

This may give you same hints: http://msdn.microsoft.com/en-us/library/aa218410(v=office.10).aspx