title: Replace the first occurrence in a string
body: <p>I have this string :</p>
  
  <pre><code>Hello my name is Marco
  </code></pre>
  
  <p>and I'd like to replace the first space (between <code>Hello</code> and <code>my</code>) with <code>&lt;br /&gt;</code>. Only the first.</p>
  
  <p>What's the best way to do it on C#/.NET 3.5?</p>