newbie needs some xhtml & xml parser help
 

I have a client that is moving their site from an apache one to an IIS
and I am going to convert existing jsp & php files to asp. I've come
across a problem that I was not expecting to have to deal with and
don't know where to even start. I've never used xml before.

Currently, there is a php page that inserts content from an external
file (different server) using php's fopen and fpassthru functions, for
which there is no equivalent that I know of in asp.

The web coordinator suggested this to me: "The research database pushes
standard xhtml snippets out when a request is made. What the snippets
contain depend on the GET variables. One method may be to use the
snippet as an XML file. The snippet is a valid XHTML file so you should
be able to use an XML parser if need be."

As I mentioned, I've never worked with xml before, so I don't know
where to start. Basically I need to get the contents of this file
(actually it could be one of 6 files depending on how the data is
sorted) which is on an external server:
http://communications.uvic.ca/resear.../topictree.php

And then I need to take the contents and have it displayed on a new
page (probably asp) in the right spot, using a local style sheet for
styling.

Please, remember I'm an idiot when it comes to this. Please keep
responses simple :-)