binary->XML translation

I am a newbie to XML, but have been coding for several years so just kind
of need a pointer of where to get started.

I have a binary data file (eventually several data files) and an XML
schema describing
the data.  I would like to parse the binary data and translate it into XML (and
eventually back to binary) using the schema.  I could just do all this with a
hand coded parser, but since the schema is likely to change over time I it
would be much better for ease and maintainability to use the schema to
generate a parser - assuming that there is a way to do this.

Any pointers in the right starting direction or tools would be greatly
appreciated.

john gay.
Denver, CO USA