Well the easiest thing that you could do is get a directional antenna of some sort and mount it facing toward the park. Foliage and wood will cause a loss but nothing that would make the connection unfeasable. If you bought a 10 -15 db antenna and connected it to the ab that **should** be enough of a boost to get

YOUR

signal to the park. As far as the laptop end i would just suggest a PCMCIA wifi card w/ an external jack.. search can help you with thatr as well as choosing an antenna
Hope it helped