url template config

[Srinivas Surapaneni]

In my beehive-url-template-config.xml, i had the following template

<url-template>
<name>jpf-action</name>
<value>
http://{url:domain}:{url:port}/{url:path}?URLTEMPLATE=action
&amp;{url:queryString}
</value>
</url-template>

When is the 
url:queryString<https://mail.google.com/mail/html/compose/static_files/queryString>used?
Is it possible to add run time paramers from request/session to this
template without extending url rewriter?

Thanks
Srinivas