title: Regex to match a pattern, but exclude a set of words
body: <p>I have been looking through SO and although this question has been answered in one scenario:</p>
  
  <p><a href="https://stackoverflow.com/questions/242698/regex-to-match-all-words-except-a-given-list">Regex to match all words except a given list</a></p>
  
  <p>It's not quite what I'm looking for. I am trying to write a regular expression which matches any string of the form [\w]+[(], but which doesn't match the three strings "cat(", "dog(" and "sheep(" specifically.</p>
  
  <p>I have been playing with lookahead and lookbehind, but I can't quite get there.  I may be overcomplicating this, so any help would be greatly appreciated.</p>