Got the solution. Instead of using the CDN exclusion list, I use the plugin (W3 Total Cache) “Page Cache” option.
Once logged in as the administrator, go to W3 Total Cache settings (a tab called “Performance”). Navigate to “Page Cache” and then to the field named “Never cache the following pages:” Finally enter the name of the page. For example, if the URL of your page is http://my_blog/random all you have to do is add the word random in the field.
It works even with a CDN set up.
P.