dih delete doc per $deleteDocById

[andreas owen]

i am using dih and want to delete indexed documents by xml-file with ids. i 
have seen $deleteDocById used in <entity query="...">

data-config.xml:
<entity name="rec" processor="XPathEntityProcessor" 
url="file:///C:\ColdFusion10\cfusion\solr\solr\tkbintranet\docImportDelete.xml" 
forEach="/docs/doc" dataSource="main" >
        <field column="$deleteDocById" xpath="//id" />  
</entity>

xml-file:
<docs>
        <doc>
                <id>2345</id>
        </doc>
</docs>