linux - Block all traffic except some from Microsoft servers and some to selected sites, with iptables

I have a D-Link router model DIR-600 with DD-WRT firmware.

I need to configure iptables so I can block all traffic, except from Microsoft servers (i.e. Microsoft updates must work), and except HTTP traffic to some selected sites.

Is it easy to do? I think someone who has Linux knowledge can do that within a few minutes.