freeswitch/conf/testing/dialplan/public/0000_local_extensions.xml

<extension name="public_extensions">
  <condition field="destination_number" expression="^(10[01][0-9])$">
    <action application="transfer" data="$1 XML default"/>
  </condition>
</extension>

<extension name="Local_Extension">
  <condition field="destination_number" expression="^(6666)$">
    <action application="bridge" data="sofia/internal/sip:888@cantina.freeswitch.org"/>
  </condition>
</extension>