XML Filters for illegal characters

Hello, I'm wondering if anyone knows of a filter that can take data to be wrapped in XML tags and filter this data encoding any illegal XML characters or, if they cannot be encoded, remove them. The problem I have is a database that contains text that must be wrapped in XML. Some of this text has illegal characters in it (probably copied from MS Word). Some of the characters that keep popping up are not very frequently used, so I'm hoping whatever filters get suggested, they can simply strip out these characters if they cannot encode them. thanks for your help. -- Doug Jones Co-Op Web Developer douglas.1.jones@lmco.com