W3 + MAX CDN won't cache wp-admin

I run a multisite where my users use mostly wp-admin backend to create pages and stuff.
I have "Host custom files" checked but nothing i enter to "Custom file list:" while using "wp-admin" or "wp-includes" url does not seem to work.
Has anyone got it working?

Because most of the work is done in wp-admin by my users, I just need the javascript and css load faster from maxCDN when they navigate in backend.

I also granted access if someone can take a look at my W3 conf.
Thanks.