title: Vim Regex Replace
body: <p>I think this is a pretty simple solution but I have been trying to find an answer for about an hour and can't seem to figure it out.</p>
  
  <p>I'm trying to do a find/replace in Vim that would replace a series of numbers that begin with <code>103</code> and are followed by four digits to <code>123</code> followed by the same four digits, as such:</p>
  
  <p><code>1033303</code> -> <code>1233303</code><br>
  <code>1033213</code> -> <code>1233213</code></p>
  
  <p>The closest I have come is this:</p>
  
  <pre><code>%s/103\d\{4}/123\0/g
  </code></pre>
  
  <p>However this results in the entire number being matched by the <code>\0</code>, as such:</p>
  
  <p><code>1033303</code> -> <code>1231033303</code></p>
  
  <p>Thank you very much for any help</p>