Setting PFSense + Squid to always cache Windows Upates

i have a satellite internet provider for internet and i do not want to always be downloading Windows updates or other programs that i download constantly for multiple computers. 


i currently have pfsense already set up with a 20GB cache that does everything from 0-5MB. 


what i am wanting (if it is possible) to set things like Microsoft Update to always cache (no matter what the size) and for it not to delete it from the cache (no matter how long it has been there). 

is this possible?

Squid-Cache FAQ is a good place to start.

thanks, were do i put these commands in at? i do not really see a place for these custom proxy settings mentioned. 

should i switch to the "Squid 3 - beta 3.1.20 pkg 2.1.0" currently i am using "Squid - 2.7.9 pkg v.4.3.4"


sorry it took a week, i closed out of the window that had this tab open and forgot about this.  i had to go in to my history to find a few other tabs i had open.