ok I can help you out here.
jboss can't do this with the deployment descriptors but if you use tomcat bundled with jboss you can do this by configuring the deploy/jbossweb-tomcat/META-INF/jboss-service.xml file.
set up a context defining your virtual host in tomcat.
and then add
in your deployment descriptor include the production site url. and automatically your war will be deployed to both hosts. even if the production url doesn't exist in the dev environment.