You need to remap your whole application to the root context - I assume this is your requirement, anyway. You can add a jboss-web.xml to your WAR deployment (in WEB-INF). It would contain the following:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE jboss-web PUBLIC "-//JBoss//DTD Web Application 2.3//EN" "http://www.jboss.org/j2ee/dtd/jboss-web_3_0.dtd">
You can view the DTD for jboss-web.xml in docs/dtd of your JBoss distribution.
Hope that is the information for which you are looking.
Thanks jonlee -- you came thru again!