XP bridge problem

We've bridged ethernet and wireless lan cards under windows xp, bridge is
working fine, but is there a program to limit traffic or even
disable it that's going to another computer behind the bridge on ethernet
network, strange thing is that some programs for network monitoring
example DUMeter or BWMeter aren't even aware of traffic that's going
throught the bridge computer, it's only aware of traffic which is
assigned directly to bridge computer, then instaling firewall on bridge
computer and trying to solve this problem with it, didn't either stop
traffic passing through it to another computer, is there any other program
you would recommend me ?
thnx