If it's an integrated wireless NIC, there is no way to attach an
external antenna to it. However, you can purchase a PCMCIA wi-fi
adapter, such as the SMC EliteConnect which on it's own should have a
long enough range to get a good signal strength on that network, and
can be hooked up to a hi-gain directional antenna if you still need a
better signal.

Ebay has some good deals on the SMC EliteConnect in 802.11b flavour,
and there shoule be an 802.11g version around too.

canoli@sbcglobal.net wrote:
> I'm using a Toshiba M35X laptop with built-in Atheros AR5005GS
> wireless network adapter. I'm trying to access a source abut 200 yards
> from me, which has a very low signal - one stick on a good day.
>
> Is there an external antenna available that will extend the range in
> order to get the signal more clearly?
>
> Canoli