Range requests to/from memory

I need to do range GETs and PUTs to/from memory. For example, someone asks
me to read bytes 300-500 of "http://www.abc.com/xyz.xml" to buffer foo.
After they modify the buffer, they will then ask me to write the buffer
back to the XML document. Range requests don't seem to work when added to a
request that is then processed by HTLoadAnchorToChunk(). Am I just going
something wrong?

I haven't yet tried the PUT side using HTPutAbsolute(), but I will if I can
get the GET working.

regards,
-jim