Seems that your router can't do that kind of traffic enforcement. Something like a used Netscreen 5GT is cheap (eBay) and can do sophisticated QoS like this (what I use).
Another option is to deploy a linux server and configure it as a router, then do qos/queuing on that.
Else, you'll have to put software on each laptop to limit bandwidth. But that only works if you are the operator of each laptop.
