title: Replace {x} tokens in strings
body: <p>We have a template URL like:</p>
  
  <pre><code>http://api.example.com/sale?auth_user=xxxxx&amp;auth_pass=xxxxx&amp;networkid={networkid}&amp;category=b2c&amp;country=IT&amp;pageid={pageid}&amp;programid=133&amp;saleid=1&amp;m={master}&amp;optinfo={optinfo}&amp;publisher={publisher}&amp;msisdn={userId}
  </code></pre>
  
  <p>and I have values for these constant tokens. How can replace all these tokens in C#?</p>