title: How can I extract a substring from a string using regular expressions?
body: <p>Let us say that I have a string "ABCDEF34GHIJKL".  How would I extract the number (in this case 34) from the string using regular expressions?  </p>
  
  <p>I know little about the regular expressions, and while I would love to learn all there is to know about it, time constraints have forced me to simply find out how this specific example would work.</p>
  
  <p>Any information would be greatly appreciated!</p>
  
  <p>Thanks</p>