I am trying to attach an XML Schema to a document as mentioned here: http://www.tech-recipes.com/rx/2099/word_2007_attach_xml_schema/

However I am having trouble attaching the schema(s) in question. I am wondering if anyone can shed light into possible reasons this is happening.

The XML Schemas I am trying to attach are these:
http://www.ddialliance.org/Specification/DDI-Lifecycle/3.1/XMLSchema/

I would like to use logicalproduct.xsd. Using the Add Schema button I know that I also need to use the following schemas: dcelements.xsd, ddi-xhtml11.xsd, simpledc20021212.xsd, xml.xsd, reusable.xsd.

However I get the following error message after adding all these schemas and trying to use them:

xml.xsd#/schema/attribute[1][@name = 'lang']
Duplicate named <attribute> : name = '{http://www.w3.org/XML/1998/namespace}lang'

Is this because Word 2007 has its own xml.xsd XML Schema that it uses that is conflicting with the one I am trying to use? Should I edit the xml.xsd that I am trying to import in any way?

How may I resolve this issue? I'm afraid I don't know too much about XML so sorry if this is a dumb question. I was just hoping to create a template on Word that used XML tags that would be compliant with this metadata standard...