Get the graphics coordinate

One task of my project is to create web pages which contain background images and icons (png) on top of it with absolute positions. The problem is that all these images already exist with the omnigraffle format. So I need to export all the graphics as separately files. I already found a script which exports all graphics (shapes, icons and background image) separately in a target folder. But now I need to know the position of each icon relative to the background image.
Do you know if is it possible to export graphics coordinates? So I will be able to place the icons in their correct position (with css) relative to the background image.