Just for the sake of argument...

There is a desktop transmitting a wireless connection. Then a laptop with a Cisco adapter picking it up and accessing the internet through it. Then a 2nd desktop with a LinkSys wireless card. Can the 2nd PC access the internet through the laptops connection? I know, why not just go from the 1st desktop? Let's say that I need to extend the wireless coverage. I'm in a straight line between all 3 machines and the 1st desktop's bubble isn't big enough to include the 2nd desktop. Can the laptop work to do that? How?