Searching for escaped characters

[Paul]

I'm trying to create a test to make sure that character sequences like
"è" are successfully converted to their equivalent utf
character (that is, in this case, "è").

So, I'd like to search my solr index using the equivalent of the
following regular expression:

&\w{1,6};

To find any escaped sequences that might have slipped through.

Is this possible? I have indexed these fields with text_lu, which
looks like this:

   <fieldtype name="text_lu" class="solr.TextField" positionIncrementGap="100">
      <analyzer>
        <tokenizer class="solr.StandardTokenizerFactory"/>
        <filter class="solr.StandardFilterFactory"/>
        <filter class="solr.LowerCaseFilterFactory"/>
      </analyzer>
    </fieldtype>

Thanks,
Paul