Processing a received XML document - support for XSD?

All,

I'm going to be receiving an XML document that I'll need to process.

I had originally intended to make use of Scott port of Expat to parse
the document.

However, apparently Expat doesn't support validating the document
against an XML Schema Document (XSD). Given that we're creating the
XSD, and a third party is supposed to be following it, having the XML
processor validate against the XSD instead of doing my own validation
in RPG would seem like a useful feature.

Is there anything on the i that I can use to validate and process the XML?

Thanks,
Charles Wilt