Match uden indre matches

Hashtable replacements = new Hashtable();
Regex reg = new Regex(@"\\[!!!(.*?)!!!\\]", RegexOptions.Singleline);
MatchCollection MatchList = reg.Matches(strInStr);
while (MatchList.Count > 0)
{
  replacements.Clear();
  for (int i = 0; i < MatchList.Count; i++)
  {
    string thisMatch = MatchList[i].ToString();
    if (thisMatch.IndexOf("[!!!", 1) < 0)
    {
      if (!replacements.Contains(thisMatch))
      {
        replacements.Add(thisMatch, null);
      }
    }
  }
  IDictionaryEnumerator _enum = replacements.GetEnumerator();
  StringBuilder builder = new StringBuilder(strInStr);
  while (_enum.MoveNext())
  {
    string thisMatch = _enum.Key.ToString();
    builder.Replace(thisMatch, TranslateItem(thisMatch, userLang));
  }
  strInStr = builder.ToString();
  MatchList = reg.Matches(strInStr);
}