title: regex submatch replace
body: <p>I'm trying to replace all occurrences of a word but only when is placed inside a pair of delimiters. Example:</p>
  
  <pre><code>Original: asdf oldfoo asdf ("asdf oldfoo asdf oldfoo asdf") asdf oldfoo asdf
  Desired:  asdf oldfoo asdf ("asdf newfoo asdf newfoo asdf") asdf oldfoo asdf
  </code></pre>
  
  <p>Is there any way to do it with <strong>sed</strong> or <strong>awk</strong>?</p>
  
  <p>Thanks!</p>