title: Replacing last x amount of numbers
body: <p>I have a PHP variable that looks a bit like this:</p>
  
  <pre><code>$id = "01922312";
  </code></pre>
  
  <p>I need to replace the last two or three numbers with another character. How can I go about doing this?</p>
  
  <p><strong>EDIT</strong> Sorry for the confusion, basically I have the variable above, and after I'm done processing it I'd like for it to look something like this:</p>
  
  <pre><code>$new = "01922xxx";
  </code></pre>