DOCBOOK-APPS: metrics tool to count xsl lines of code?

Hi there,
  Does anyone know of a (preferably free) metrics tool that counts lines of .xsl code?  We'd need something that would exclude white space and comments, and not count something like this:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                xmlns:xt="http://www.jclark.com/xt"
                extension-element-prefixes="xt"
              version='1.0'>
 as 4 lines just because it's formatted that way.

We need it to do some planning and estimating for a project that involves writing and modifying .xsl stylesheets.

Any ideas?

Thanks,

 Trish Billard