title: Regular expression to match from the end of a match condition
body: <p>I want to match from the end of a result from a or condition in <strong>regular expression</strong>.</p>
  
  <pre><code>$a = 'SI-#CL#¤1801 BARBER LANE#CL#MILPITAS CA 95035#CL#FONE 1-408-943-0600#CL#FAX 1-408-943-0484#CL#¤CANCEL BY 5 PM - RQST-NO FEATHER';
  $pat = '/^(?(?=SI)(?&lt;matchfromend&gt;[A-Z]+$)|(?&lt;else&gt;.*))/';
  </code></pre>
  
  <p>i want to match <strong>CANCEL BY 5 PM - RQST-NO FEATHER</strong> only if string starts from <strong>SI-</strong></p>
  
  <p>Any suggestion ??</p>
  
  <p>Thanks</p>