title: Excluding specific regex match from general regex match
body: <p>I have been trying various combos and cannot seem to get the regex I need for a C# .Net application.  </p>
  
  <p>I have a text document that can contain the following :</p>
  
  <pre><code>{{{3456764345345}}} yadda yadda yadda {{{xyz}}} 
  </code></pre>
  
  <p>{{{3456764345345}}} can have any alpha-numeric value in it and will be different per document, while {{{xyz}} will always be {{{xyz}}} initially.</p>
  
  <p>So, you could have the following documents:</p>
  
  <pre><code>{{{3456764345345}}} yadda yadda yadda {{{xyz}}} 
  {{{45435555}}} yadda yadda yadda {{{xyz}}} 
  {{{54727r475t76777a4}}} yadda yadda yadda {{{xyz}}} 
  </code></pre>
  
  <p>I  want to replace both {{{3456764345345}}} and {{{xyz}}} with different values. The problem is when I try to replace {{{3456764345345}}} it replaces itself and {{{xyz}}} making it so I am unable to replace the second value.  </p>
  
  <p>I am currently using: </p>
  
  <pre><code>{{{.*?}}} 
  </code></pre>
  
  <p>as my expression.  This works to find the first but it also includes the second.  </p>
  
  <p>I need an expression that allows me to find the first value but exclude the {{{xyz}}} value. </p>
  
  <p>Thanks in advance.  </p>