title: Replace leading spaces with Notepad++
body: <p>I'd like to use Notepad++ to replace all leading spaces on a line with a like number of given characters. So for instance, I want to change:</p>
  
  <pre><code>zero
   one
    two
     three
  </code></pre>
  
  <p>into:</p>
  
  <pre><code>zero
  @one
  @@two
  @@@three
  </code></pre>
  
  <p>I haven't been successful at getting this working. I did find <a href="https://stackoverflow.com/questions/4683021/regex-to-replace-html-whitespace-and-leading-whitespace-in-notepad">Regex to replace html whitespace and leading whitespace in notepad++</a>, but wasn't able to get the result I wanted.</p>
  
  <p>Is this possible with Notepad++? I'd rather not have to write code to do this...</p>