To do something like that you will need to filter an upper layer than IP. So, it depend on the protocol you will use ( ftp, http, etc ). If you say us why do you need that, it is possible that someone can help you. If you need that with all the traffic to those hosts, the answer is you can't.
Matias Lambert OSInet Telecomunicaciones Capital Federal - Buenos Aires Argentina - CA1185ACA http://www.osinet.com.ar
