I am planning to do the same soon, but have not yet looked at this.
May be look at the tomcat root server :
I think it's this one that handle the request first, and when a resource is not found (ie: before the portal servlet that are in the portal-server.war)
It is configured as a JMX service
Looking at JBoss AS forum and wiki may help... probably yet answered there...
(please consider putting the answer in this forum, when you have it... thanks)