How to set "use only configured seed rendezvous" attribute using ext.config.Configurator?

Hi,

When i configure my jxta nodes i need to activatethe option "[ ] Use 
only configured seed rendezvous" that appears in the default jxta 
configurator. I need to change this setting from the platform config:

<Parm type="jxta:RdvConfig" config="client" xmlns:jxta="http://jxta.org">
            <seeds useOnlySeeds="true">
                <addr>
                    http://x.x.x.x:9700
                </addr>
                <addr seeding="true">
                    http://rdv.jxtahosts.net/cgi-bin/rendezvous.cgi?2
                </addr>
            </seeds>
        </Parm>

I want to change this config with this another one:

<Parm type="jxta:RdvConfig" config="client" xmlns:jxta="http://jxta.org">
            <seeds useOnlySeeds="true">
                <addr>
                    http://x.x.x.x:9700
                </addr>
                <addr seeding="*false*">              
                </addr>
            </seeds>
        </Parm>

What is the best way to do this using the API packaged in 
net.jxta.ext.config?

Thank you very much

Joan