Sample expat code for reading entities?

I have an XML file which has a DTD (that I don't want to read) and 
another external set of decls ref'ed from the internal subset, which 
contains some entity declarations that I do need).  This is in C code. 
I'm plowing through the expat docs and the write-up on things like 
XML_SetExternalEntityHandler is giving me a headache.  I'm sure I can 
figure it out, but are there some implementations out there to look at 
and make this go quicker?
-- 
Cheers, Tim Bray
         (ongoing fragmented essay: http://www.tbray.org/ongoing/)