It needs to be a Wifi router/ap (hub)... not bluetooth. Are you sure it's not WiFi, because Wii won't connect to bluetooth APs.
Also, you may not even need a code... it's amazing how many people don't use codes or keys in the setup of their WiFi equipoment.
If you don't know the key, you'll have to refer to your Wireless vendor's instructions on how to change your code or key... for security you may not be able to read the existing key, if one exists.
This is a start...