MatchCollection match = Regex.Matches( fileText, pattern, RegexOptions.IgnoreCase | RegexOptions.Multiline );

if( match.Count > 0 )
{
   StringBuilder sb = new StringBuilder();
   IEnumerator m = match.GetEnumerator();
   for( int i = 0; i < match.Count; ++i )
   {
      sb.AppendFormat("{0}\n",match[i].Value.Trim());
   }
   
   return sb.ToString();
}
else
   return String.Empty;