conf/dialplan/default.xml for the group:
    <extension name="group_dial_support">
      <condition field="destination_number" expression="^2001$">
      <action application="set" data="call_timeout=20"/>
      <action application="set" data="continue_on_fail=true"/>
      <action application="set" data="hangup_after_bridge=true"/>
      <action application="bridge" data="group/support@${domain_name}"/>
      <action application="answer"/>
      <action application="sleep" data="2000"/>
      <action application="voicemail" data="default 2600"/>
      </condition>
    </extension>