Block some hosts

Hi! i want to block some hosts (malware sites that downloads trojans), like this: http://letters.letters.* . * is a random continue of host (numbers or letters).
And to block this host: http:\* i went to Firewall/Common tasks/My Blocked Network Zones/Add/A New Blocked Adress /A host name/ and there i put (without http://). That blocks the host (and the *)?

Ty for your help.