title: Using regex to reformat text
body: <p>Is there a way to use regex to reformat a string?</p>
  
  <p>I've a string like this <code>AEY4293</code> and I want to add a dash between letters and numbers, like this <code>AEY-4293</code>.</p>
  
  <p>I was trying to find something like <code>s/pattern/replacement/</code>, but I couldn't find it.</p>
  
  <p>I can select the blocks using <code>/(\w+)(\d+)/</code> so if I could give to a pattern to reformat the text like <code>\1-\2</code> it would be great.</p>
  
  <p>Thanks!</p>