DOCBOOK-APPS: Website DTD XSLT conversion in multi-machine evironmentproblem

Hi DocBook users,

consider this problem:

we have a CVS repository to share out DocBook Website documents, and
use a customized XSLT stylesheet for converting this documents to
HTML. It starts like:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                xmlns:saxon="http://icl.com/saxon"
                BLA BLA>

<xsl:include href="/usr/lib/sgml/stylesheet/xsl/docbook/nwalsh/website/1.9/chunk-tabular.xsl"/>
<!--xsl:include href="/documents/config/xml/website/xsl/chunk-tabular.xsl"/-->
 
<xsl:template match="homepage">
  THE REST
</xsl:stylesheet>

And you can see the problem of the multi platform in this case: the website stylesheets are
not always in the same place...

I tried:

<xsl:param name="stylesheet">/documents/config/xml/website/xsl/chunk-tabular.xsl</xsl:param>
<!-- this is the default -->

<xsl:include href="$stylesheet"/>

Which i could overwrite using Xalan with:

java -cp ${CLASSPATH} org.apache.xalan.xslt.Process -IN website.xml -XSL website.xsl \
     -PARAM stylesheet "/usr/lib/sgml/stylesheet/xsl/docbook/nwalsh/website/1.9/chunk-tabular.xsl"

However, Xalan does not substitute the $stylesheet with its value, and i get an error
that it cannot find the stylesheet "$stylesheet"... :(

Can oneone explain how i can solve this problem?

greetings,

Egon