Rather than a wireless router you need a wireless access point. Routers tend to be more for ADSL lines - you plug it into your phone line with your ADSL connection and it provides you with a wireless network and sometimes a few normal ethernet connections.

A wireless access point is designed to be plugged into an ethernet port and provides wireless networking from there.

Some ADSL wireless routers can be used without the ADSL port as a normal wireless router.

A wireless access point will cost you anything between about 30 and 60 euros depending on the make.

You can get one from the computer shop in the corner near the Ajuntament in Tortosa. I think PC City and Media Mart also sell them if you are up in the Reus area.

Nigel