Changing the URL of resources?

Right now all of my URLs in my HTML docbooks are relative to the
location of the HTML.  Is there a way to seperate those static
resources like images and change the location?  So I could have my
docbook HTML served from one URL under a tomcat instance and serve all
the static content on an Apache server?  I'm modifying the resulting
docbook HTML through a servlet before sending it to the browser is why
I ask.

Charlie