question about relaying a wireless broadcast

I have a Netgear WG311 PCI access card installed in a desktop computer.
I am sharing Internet access with a neighbor but the reception where
the desktop is located is only marginally adequate. On the other hand,
a friend's laptop showed a much stronger signal in a different room
compared to when located in the room where the desktop is.

What kind of free standing wifi device do I need? I want to place it
where the laptop showed the strongest signal in order to relay or
propagate it to the PCI card in the desktop, which would then
presumably be stronger than that currently being receiving. I haven't
been able to find a product for this function on the various wifi
manufacturers Web sites. Is what I want to do possible or feasible?

I was also wondering whether a wireless G ethernet device would work if
I ran an ethernet cable from it to the desktop.

If you have specific product(s) you can recommend, I would very much
appreciate it.

Thanks in advance.

Neil Ross