title: Regex for xxxx.xxx.xxx
body: <p>I need to validate a Vat number.</p>
  
  <p>xxxx.xxx.xxx --> 0123.456.789 is a valid number.</p>
  
  <p>I found a regex </p>
  
  <pre><code>^(BE)[0-1]{1}[0-9]{9}$|^((BE)|(BE ))[0-1]{1}(\d{3})([.]{1})(\d{3})([.]{1})(\d{3})
  </code></pre>
  
  <p>This validate the following entry: BE 0123.456.789.</p>
  
  <p>But what i need is to validate only xxxx.xxx.xxx ( nothing else is valid , only this )</p>
  
  <p>So 4 digits , a point , 3 digits , a point , 3 digits.</p>
  
  <p>Also it needs to begin with 0 or 1 ( first x --> 0 or 1 )</p>