title: Regular expression excluding subpatterns
body: <p>I have got codes to match with a very simple string pattern:
  <code>XXnnnnnnnnn (2 alphanumeric, 9 numeric)</code>.</p>
  
  <p>I am using this regex:
  <code>\w{2}\d{9}</code>.</p>
  
  <p>Now I am required to excude from matching any string that begins with the constant token '<code>AY</code>', and any string with 11 repeated character (e.g. '<code>11111111111</code>' or '<code>00000000000</code>').</p>
  
  <p>How may I exlude subpatterns using regular expressions?</p>