title: Creating Regex expression for hard coded digits in a string
body: <p>I need to create a regex expressions. Basically i am trying to search if the number is valid or not.</p>
  
  <p>Number Format is <code>923 x g yyyyyyy</code></p>
  
  <p>I want regex which detects starting three to be <code>923</code> , then x should be less than 7 and g and y can be any numbers from <code>0-9.</code> i HAVE tried understanding regex but i can't find anything .</p>
  
  <p>Anyone can make regex and then explain a little how it actually works</p>