[squid-users] blocking some ip's for some websites.

Hello,
Can we use squid to block some IP's from accessing some sites

let's say

I am using 172.16.0.0 in my internal network and I want to block these ip's
172.16.20.12
172.16.20.14
172.16.20.23
172.16.20.120
172.16.20.45
172.16.20.67
172.16.20.89

from accessing "mail.yahoo.com" ,hotmail.com (May be regex required
for *.mail.yahoo.* , *.hotmail.* , and *.messenger.msn.com ) and MSN
Messenger..
How should I proceed with this setup so that only these users are
effected and rest of all are allowed to brows any website on Internet
cloud.

Regards,

-- 
Nasir Mahmood
Systems  Administrator.