title: How to replace the first match only using .Net Regex.Replace
body: <pre><code>Regex.Replace("a b c a b c", "a", "*")
  </code></pre>
  
  <p>returns</p>
  
  <pre><code>"* b c * b c"
  </code></pre>
  
  <p>Is there a simple way to replace only the first occurence, such that the result is</p>
  
  <pre><code>"* b c a b c"
  </code></pre>
  
  <p>Cannot find a RegExOption that would limit the replacement. In particular</p>
  
  <pre><code>Regex.Replace("a b c a b c", "a", "*", RegexOptions.Multiline)
  Regex.Replace("a b c a b c", "a", "*", RegexOptions.Singleline)
  </code></pre>
  
  <p>do not make any difference - obviously. There are not much more options however.</p>