Defining an XML Fragment in W3C Schema

Hi,

I have a need to define an XML fragment in a W3C schema. In other words,
an element or attribute in the schema should be able to contain an XML
fragment, with the parser recognizing this XML fragment as actual data
rather than part of the XML document.

I've researched XML Fragments, and I also understand that CDATA was part
of the W3C Schema specification at one point but did not make it into
the final version.  Can anyone please suggest a way to accomplish this?

Much appreciated,

Joe Chiusano
Booz | Allen | Hamilton