title: Match digits in regex statement
body: <p>My goal is to capture the last page of the report and I want to achieve it by matching the header that describes the page numbers. 
  My last page of the report contains the following string that I want to match (it could be also a two digit or four digit number as well):</p>
  
  <blockquote>
    <p>Page: 877 of 877</p>
  </blockquote>
  
  <p>The regex that I tried to use is</p>
  
  <pre><code>Page:\s (\d+) of \1
  </code></pre>
  
  <p>but this captures the following case as well:</p>
  
  <blockquote>
    <p>Page: 8 of 877</p>
  </blockquote>
  
  <p>I understand the regex expressions are read left to right but is there a way to capture the second number, 877, and then match it with the first number? (some kind of back refernece)
  I use regex engine of the .NET Framework.</p>