Unfortunately, by escaping all the markup, you've made the data very inaccessible. It's a shame to use XML this way - the whole point of the markup is to create useful structure which adds value to your information, and escaping it to hide the structure seems a really bad idea because it removes all this added value.
What you need to do here is to double-parse the content of the <entry> element. The first parse gives you the content of the <entry> element as text; you then need to feed this back into an XML (or HTML) parser to turn it into a tree, which you can navigate using XPath. At first sight it looks as if the content is well-formed XML, which means you can parse it in Saxon using the saxon:parse() extension function, or in another processor you could write your own extension function to take a string as input and return the parsed document tree.
Author, XSLT 2.0 and XPath 2.0 Programmer's Reference