title: Replace all td's in first tr PHP pregmatch (REGEX)
body: <p>I want to replace all td's with th's for only the first tr.
  But I cannot really figure out how to do this using Regex in PHP.
  (replace the td at all)</p>
  
  <pre><code>     &lt;tr class="row0 row-hover"&gt;
          &lt;td class="column-0 "&gt;&lt;?php _e('Data', 'domain'); ?&gt; &lt;/td&gt;
          &lt;td class="column-0 "&gt;USD&lt;/td&gt;
          &lt;td class="column-0 "&gt;EUR&lt;/td&gt;
          &lt;td class="column-0 "&gt;GBP&lt;/td&gt;
          &lt;td class="column-0 "&gt;CAD&lt;/td&gt;
          &lt;td class="column-0 "&gt;CHF&lt;/td&gt;
          &lt;td class="column-0 "&gt;HKD&lt;/td&gt;
          &lt;td class="column-0 "&gt;AUD&lt;/td&gt;
          &lt;td class="column-0 "&gt;SGD&lt;/td&gt;
          &lt;td class="column-0 "&gt;SEK&lt;/td&gt;
          &lt;td class="column-0 "&gt;NOK&lt;/td&gt;
          &lt;td class="column-0 "&gt;CNH&lt;/td&gt;
        &lt;/tr&gt;
  </code></pre>
  
  <p>First of all I have there markup.
  I try to match them using <code>&lt;tr.*\(&lt;td&gt;).*\</code>. But that don't seem to work. I know that I have to firstly match on the (.*). But I cannot get the td's.</p>
  
  <p>The second thing would be use the <code>preg_replace</code> replace function. I saw that you can set here an $limit. So that would be just one? And what is the best way to group this for the preg_replace function?</p>
  
  <p>It would be nice if it becomes this :)</p>
  
  <pre><code>         &lt;tr class="row0 row-hover"&gt;
              &lt;th class="column-0 "&gt;&lt;?php _e('Data', 'domain'); ?&gt; &lt;/th&gt;
              &lt;th class="column-0 "&gt;USD&lt;/th&gt;
              &lt;th class="column-0 "&gt;EUR&lt;/th&gt;
              &lt;th class="column-0 "&gt;GBP&lt;/th&gt;
              &lt;th class="column-0 "&gt;CAD&lt;/th&gt;
              &lt;th class="column-0 "&gt;CHF&lt;/th&gt;
              &lt;th class="column-0 "&gt;HKD&lt;/th&gt;
              &lt;th class="column-0 "&gt;AUD&lt;/th&gt;
              &lt;th class="column-0 "&gt;SGD&lt;/th&gt;
              &lt;th class="column-0 "&gt;SEK&lt;/th&gt;
              &lt;th class="column-0 "&gt;NOK&lt;/th&gt;
              &lt;th class="column-0 "&gt;CNH&lt;/th&gt;
            &lt;/tr&gt;
  
  </code></pre>