@XMLXPATH[["filename"],path] : XML XPath query. (See the XML XPath docs for details on XPath syntax.) The arguments are:
filename - name of XML file
path - one or more element accessors separated by a /.
If you don't specify a filename (which *must* be in double quotes), @XMLXPATH will use the XML file previously opened by @XMLOPEN.
To return an attribute, preface the attribute name with an @.