Here is a very simple XML Schema, but unfortunately Excel doesn't like it as it has "list of lists" in it. There can be many anchors that each have many attributes, for examle.
Anchor.xsdIt would, otherwise, have been an easy way to get XML according to the schema used by the tool. Note though that this schema just contains the bare minimum for a model. If you need a complete schema I can try to put one together for you?