title: I need a GREP expression that will find 6 - 10 digits, separated by periods at the 1000 intervals. The periods could be spaces or not at all
body: <p>I need a GREP expression that will find 6 - 10 digits, separated by periods at the 1000 intervals. The periods could be spaces or not at all.  It must find: </p>
  
  <pre><code>3.878.456.789   
    878.456.789   
     78.456.789   
      8.456.789   
        456.789    
  3 878 456 789     
    878 456 789    
     78 456 789    
      8 456 789   
        456 789   
     3878456789     
      878456789    
       78456789    
        8456789   
         456789  
  </code></pre>
  
  <p>These numbers could be any digit and aren't bound by those in the example.  The example was given to show the length and pattern for spaces or periods. </p>