I'm curious if you found your answer. I have the same 'issue', except for different reasons. Simply, I want to define an environment entry outside the war.
Something equivalent to tomcat's 'Environment' tag in a context descriptor (which we keep in /conf/Catalina/localhost) would be nice.
have you considered using a session bean to distribute properties (making an env-entry in the ejb-jar.xml for each property)?
another possibility is to deploy a properties file and read it from a session bean with getResourceAsStream(...).