title: C# RegEx match beginning of string and beginning of word simultaneously
body: <p>Say there are six strings</p>
  
  <ol>
  <li>"abcd bbb ccc"</li>
  <li>"abce bbb ccc"</li>
  <li><p>"abcf bbb ccc"</p></li>
  <li><p>"aaa abcd ccc"</p></li>
  <li>"aaa abce ccc"</li>
  <li>"aaa abcf ccc"</li>
  </ol>
  
  <p>User enters expression "<code>&lt;abc[!e]</code>"</p>
  
  <p>This expression gets translated into following regex "^abc[^e]"</p>
  
  <p>Translated regex would successfully match strings 1 and 3</p>
  
  <p>If I wanted to match strings 4 and 6 the expression has to be translated into "\Wabc[^e]" (this would also match space before abc chars :(, which is not good)</p>
  
  <p>Unfortunately user entered expression needs to be converted in regex that would match both 1,3 and 4,6 strings. </p>
  
  <p>Is there way to translate user entered expression into regex that would combine "^abc[^e]" and "\Wabc[^e]" expressions (ideally second expression would not match first space :) )</p>