title: Regex for Password: "Atleast 1 letter, 1 number, 1 special character and SHOULD NOT start with a special character"
body: <p>I need a regular expression for a password field.</p>
  
  <p>The requirement is:</p>
  
  <ol>
  <li><p>The password Must be 8 to 20 characters in length</p></li>
  <li><p>Must contain at least <strong>one letter</strong> and <strong>one number</strong> and a special character from <strong><code>!@#$%^&amp;*()_+</code></strong>. </p></li>
  <li><p><strong>Should not start with a special character</strong></p></li>
  </ol>
  
  <p>I have tried</p>
  
  <pre><code>^(?=.*[a-zA-Z])(?=.*\d)(?=.*[!@#$%^&amp;*()_+])[A-Za-z\d!@#$%^&amp;*()_+]{8,20}
  </code></pre>
  
  <p>It works but how do you restrict special characters from beginning the password? Also if you have a more efficient regex than the one mentioned above please suggest.</p>
  
  <p>Thank you</p>