My suggestion would be to extend   XML::Xalan, a Perl interface to Xalan-C++. This lets you apply a (potentially dynamically generated) XSL transformation to an XML document. Example from the docs:

  use XML::Xalan;

  my $tr = new XML::Xalan::Transformer;
  # parse an XML string:
  my $parsed = $tr->parse_string(<<"XML");
  <?xml version="1.0"?>
  <doc>Hello</doc>
  XML

  # compile a stylesheet string:
  my $compiled = $tr->compile_stylesheet_string(<<"XSLT");
  <?xml version="1.0"?> 
  <xsl:stylesheet
       xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
       version="1.0">
    <xsl:template match="doc">
      <out><xsl:value-of select="."/></out>
    </xsl:template>
  </xsl:stylesheet>
  XSLT

  my $res = $tr->transform_to_data($parsed, $compiled);
[download]