title: RegEx for matching any 2 letters + any 6 numbers in lucene
body: <p>I'm writing an Exclude filter for Significant Terms aggregation in Elastic Search. I want to exclude from the results any terms matching the pattern (any 2 letters)(any 6 numbers) ie AB123456</p>
  
  <p>I tried:</p>
  
  <pre><code>[a-zA-Z]{2}&amp;&lt;0-9&gt;{6}
  </code></pre>
  
  <p>but Kibana gives an error when I try to update my visualization</p>
  
  <pre><code>[x_content_parse_exception] [1:72] [significant_terms] exclude doesn't support values of type: START_OBJECT
  </code></pre>
  
  <p>This JavaScript seems to do what I want:</p>
  
  <pre><code>([a-zA-Z]{2}\d{6})
  </code></pre>
  
  <p>but I'm struggling to translate it to Lucene</p>