Override Weblogic config.xml values with weblogic.Server JVM property

Oracle® Fusion Middleware Command Reference for Oracle WebLogic Server
11g Release 1 (10.3.1)
weblogic.Server Command-Line Reference

When you use a startup option to override a configuration value, the server instance uses this value for the duration of its life cycle

http://download.oracle.com/docs/cd/E12839_01/web.1111/e13749/weblogicserver.htm#i1031832

For to override listen address stored in config.xml add in start script
-Dweblogic.ListenAddress=host

This startup option overrides any listen address value specified in the config.xml file. The override applies to the current server instantiation; it does not modify the value in the config.xml file. Use the Administration Console or WLST to modify the config.xml file.