Using Subobject Maps in ACP

Hi,
Can anyone guide on how to use Subobject  Maps in ACP ?

Tried using it in this way...

<rename>
    <subobject_maps>
        <lists>
            <list apiname="TestList">
                <list_entries>
                    <map>
                        <source_apiname>33</source_apiname>
                        <target_apiname>44</target_apiname>
                    </map>
                </list_entries>
            </list>
        </lists>
    </subobject_maps>
</rename>

To rename a list entry..... but it does not work....



Thanks