Adapt Saxon I18N Support Library for Xalan

Hi
I was going to use the I18N Support Library which has been modified by Antenna
House:
http://www.antennahouse.com/XSLsample/XSLsample.htm

They note that the core functions are processor independent but the current
implementation has been built with the Saxon processor in mind.

To support Xalan I will need to adapt a class file that extends the
"ExtensionElementFactory" and makes use of the following two packages:
com.icl.saxon.expr.SingletonNodeSet;
com.icl.saxon.expr.XPathException;

Although the interface "ExtensionElementFactory" only contains one method
"getExtensionClass" which is not actually used.

Does anyone know the equivalent packages or have any advice on how I can adapt
it for the Xalan processor, or indeed any other i18n library that supports
Xalan out the box?

Thanks