Im not sure if this is the answer to the question your asking (its a little unclear), but to specify a JBoss datasource you need to add an entry to your "jboss.jcml" file, in /conf/default. It should look something like this...
Obviously replacing the stuff in 's with the appropriate values.
Hope this helps,
If using Jaws you also have to specify your datasource in jaws.xml.
Thank Julia, this is what I need!