Handling include statements in XML files

The XML files which I am attempting to parse with expat 2.0.0 have 
include statements which I presently can handle.

I've attempted to create a new parser via the 
XML_ExternalEntityParserCreate function, but I am not sure what the 
"context" parameter needs to be.  What should it be?

The include XML file is of the same type as the original, so I want all 
exiting handlers to work with the included file.