Which technology? Which XML parser? XQL?

I want to create a simple application in MFC, and what my application does is as following,
- be able to read xml document from a http server, parse it, query it, and display the result on the client window.
- more than one clients are able to modify the xml document on the http server.

I'm kinda confused which technology I should use. I did a research and there are a lot of tools out there, and since I am not very familiar with xml yet, I have difficulty to decide which one is the best for my needs and the easiest one to interface with mfc application.
I don't want to write my own xml parser. I just want to use the one that is available out there that suits my needs.

which xml parser? Xerces or msxml? Do I need xql library to query xml document?