You could direct and localize the radio transmisisons but it wouldn't be something most people would accept. You could fashion something as trivial as aluminum foil in a concave "radiation director" around the laptop. That would capture signal coming in and direct what's coming out. It could be effective but would be tacky and for a laptop for sure, not really practical.
Better NIC with a better quality radio would be an option. ie..better signal to noise ratio, more powerful power to the antenna etc..