<xsl:value-of select="exslt:node-set($theResult)"/>
where you bind exslt (or whatever prefix you like) to "http://exslt.org/common"

<xsl:value-of select="saxon:node-set($theResult)"/>
where you bind saxon (or whatever prefix you like) to "http://saxon.sf.net" (but I remember saxon supports exslt extensions, so you can use the previous

Cheers,
Abel Braaksma
http://www.nuntia.nl

I've tried it but I receive an:

SystemID: xxx.xsl
Location: 98:0
Description: The URI urn:schemas-microsoft-com:xslt does not identify an external Java class

error message at this location:

      </xsl:variable>
      <xsl:value-of select="msxsl:node-set($theResult)"/> <!-- here -->
   </xsl:template>

???

Thanks for your help!
Markus