In case anybody visits this node again, I have a guess what sandy1028 is talking about. HTML (and XHTML) define a set of named character entities such as . Generic XML parsers will not recognize these entities because they are application specific. So he or she needs, for whatever reason, to translate XHTML-specific named character entities to their corresponding numeric character entities for use in some non-HTML XML application.
A few years ago I had to do this myself when reformatting some good old-fashioned HTML into something that could be used in an XSLT stylesheet. Man was that a pain.