@Astral
It sounds like you're trying to set up dial up preferences, you don't need to set up a l/p since connection to the provider is handled by the adsl modem. If it is a new modem (not one configured to connect to your provider via another machine) then you will need to enter the html pages of the actual modem and enter the login details there!
If anything you probably just need to tweak the mask settings and static ip ranges (a router tends to assign these itself) for the ethernet connection option.
I'm at work so I can't provide mine, I have no trouble connecting via a dlink router or a dlink modem.
Study the webpages of your Provider and take note of the details you need to enter. Use OWB/IBrowse to login to your modem and make sure the settings are compatiable with the settings conveyed from the Provider information and your user details.
This might all sound a little daunting but it's just detective work and a little learning curve of terminology blues
good luck