title: Move programmatically cursor in UiTextField
body: <p>I need to tweak UiTextField behavior so that I can programmatically insert some asterisks and move the cursor at the beginning of the string;
  I tried the "paste" trick (<a href="http://dev.ragfield.com/2009/09/insert-text-at-current-cursor-location.html" rel="noreferrer">http://dev.ragfield.com/2009/09/insert-text-at-current-cursor-location.html)</a>, but the cursor is moved at the end.
  The effect I try to achieve is like this:
  At the start:</p>
  
  <hr>
  
  <p>then the user insert characters
  f*****
  fo****
  foo***
  etc...</p>
  
  <p>Is this possible or the tweaks I've to do don't deserve the effort?</p>
  
  <p>Thanx</p>
  
  <p>-G-</p>