title: Regex for fixed position and length field
body: <p>I am working on a regex to extract exact characters from a mainframe log line with fixed width spacing (...regex is not my strong suit, BTW).  </p>
  
  <p>I want to extract out the field values for a Status field, which is the fixed-length field that contains the <code>SUCCESSFUL AUDIT</code>, <code>LOGON COMPLETE</code>, and <code>FINAL FAILED AUDIT</code> values shown in the sample events below.</p>
  
  <p>There are many values for this fixed-length field, so I can't really extract out the literal string values like I was trying to do. </p>
  
  <p>Instead, I would like to extract out any characters that start at position 54 of the event and the length is <em>exactly 18 chars</em>.</p>
  
  <p>Any help or ideas regarding the regex or the method, etc, would be greatly appreciated.</p>
  
  <pre><code>528 LOGON   39690  SECURITY LAPTOP    8481 USER AB11 SUCCESSFUL AUDIT  BBB908AFB 06/20/12 09:11:43PM    
  528 LOGON   39692  SECURITY LAPTOP    8495 USER AB11 LOGON COMPLETE    BBB908AFB 06/20/12 09:12:12PM    
  528 LOGOFF  39699  SECURITY DESKTOP   4476 USER ABEQ FINAL FAILED AUDITAADAFCC01 06/20/12 09:55:49PM   
  </code></pre>