In one pc I have an USB Wifi adapter (Realtek RTL8187L Chipset), from there a 10 meters cable to an outdoor antenna. With that I connect to a public Access Point.

Now I want to be able to connect more computers to internet using that same connection that comes from the outdoor antenna, what options do I have to do this?

I do have another usb wifi adapter with a small omni antenna, and a router encore ENHWI-G/A. This router can be used as a Wifi AP, but it needs a modem that works with the RJ45 connector.

Is there a way I could take internet from the outdoor antenna, and create another AP indoor using that router to "repeat" that wifi that comes from the outdoor antenna?

If creating this second AP is not possible, should I use some sort of local network between computers, connect my main PC with the outdoor antenna, and share the connection through the lan? (I would really prefer to have a second AP indoor so I can connect other devices like a Palm, but I am not sure how could this be possible with this router and the usb wifi adapter)