Sun J2EE server (default with J2EE package) + PostgreSQL jdbc support

I have PostgreSQL 7.2.2 and (jdbc driver jdbc7.2dev-1.2.jar
 is located in /usr/share/pgsql/ ). I'm writing a project where I use
 technolgies like : Apache 1.3.27 + Tomcat 4.1.18 + Struts 1.x + ANT for
 XML files + Sun (default) J2EE 1.3.1 server.

     The problem is that I don't know how to set up PostgreSQL driver
 to be used with J2EE server (is it possible ?). I downloaded from the Sun
 site J2EETutorial, and bank example. To run this example I need
 use J2EE server, which is default delivered and configured with
 Cloudscape  database. There is a file called $J2EE_HOME/config/resource.properties
 with settings for Cloudscape database. There is also a build.xml
 file in the bank directory which builds classes,jars,ears etc. from
 sources. Cloudscape setings are :

   <property name="cloud-lib" value="${myenv.J2EE_HOME}/lib/cloudscape" />
     <property name="system-lib" value="${myenv.J2EE_HOME}/lib/system" />
     <property name="cloud-path" value=".:${cloud-lib}/cloudclient.jar:${cloud-lib}/RmiJdbc.jar:
     ${system-lib}/cloudutil.jar:${system-lib}/cloudscape.jar"/>
     <property name="cloud-jvmargs" value="-ms16m -mx32m
-Dij.connection.CloudscapeDB=jdbc:rmi://localhost:1099/jdbc:cloudscape:
 CloudscapeDB;create=true -Dcloudscape.system.home=${myenv.J2EE_HOME}\cloudscape" />

 The whole thing is about how to change Cloudscape to PostgreSQL (ant
 config + resource.properties + JNDI in source files) ?

 I'll be very grsteful if anyone know the answer !

 Greetings,
 Patryk