No you can't, only full hostnames (like if you wanted to block YouTube, you would need to put both youtube.com and
www.youtube.com into the HOSTS file, no wildcards allowed); also this one is better because it is smaller (huge HOSTS files slow down your TCP/IP stack) and has fewer false positives:
http://pgl.yoyo.org/as/serverlist.php?hostformat=hosts&showintro=0&useip=0.0.0.0&mimetype=plaintext
Also consider using HostsMan to automate the updating of your HOSTS file and to optimize it (so the "disable DNS Client" suggestion may not even be necessary):
http://www.abelhadigital.com/hostsman
If you do want to block specific IP addresses, use PeerBlock:
http://www.peerblock.com/releases
I have posted a guide about the use of PeerBlock:
https://code.google.com/p/jansal/wiki/PeerBlock
As for an IE9-specific solution (one that can block specific URL patterns, even using some wildcards), try the Main and Stats lists from Fanboy, who has converted his Adblock Plus subscriptions into Tracking Protection Lists:
http://fanboy.co.nz/ie.html