syntax highlighting in webhelp format

Is anyone syntax highlighting programlistings in webhelp format?

I use the maven-docbkx-plugin and in 
HTML and PDF output, I add the following to my customization layer:

  <xsl:import href="urn:docbkx:stylesheet/highlight.xsl"/>

But there is no highlight.xsl file in the webhelp directory. 

Is there any other way of doing this?

Nat