External scripts

Hi,

Did anyone have success in minifying (or caching) external files?
Like example:
http://www.google-analytics.com/analytics.js

Its just one of the files that I see when I check our site via google page insight. I wanna know if there is a work around for this or not.

Thanks!

https://wordpress.org/plugins/w3-total-cache/