custom navigation for a project outside boost

Hi !

I'm using boostbook (and quickbook) to generate the documentation for a 
library outside of boost.
I like the look of the boost navigation header but would like to replace 
the links with some of my owns (I was able to replace the image).
So ideally I'm looking for a way to customize the "header.navdata-horiz" 
xsl:template from tools/boostbook/xsl/navbar.xsl somehow.

I found this post from 2007 
http://boost.2283326.n4.nabble.com/boostbook-woes-take-1-td2630151.html 
asking for being able to add a local customization layer for dockbook.
Is this a now supported feature ?

Thank you !

Regards,
MAT.