How would I pull a simple piece of information out of a large xml string

I am trying to create a filter in .net to block users from seeing Search results they cannot access. My idea开发者_运维知识库 because I have very little access to the search engine itself, is to search with the search tool, pass the information via xml through my custom filter, and then output to xsl. Right now I am to the point where I am trying to figure out how to read, and break apart single parts of the large xml string I have retrieved from the search tool with HttpWebResponse, and Streamreader.

How would I go about breaking this string into a usable format?

You could use a XmlReader if the XML is large to avoid loading it in memory before parsing. If the XML is not very big XDocument is very good and could be used to read and extract information from a XML file.