Try set it up in router mode so it creates its own connection then just try establish a PPPOE from a PC and see if it works, I found out on Wednesday by accident that it works that way with the D-Link DSL-2640U.
It doesnt work that way, already tried, currently my router is on PPPOE mode (where i enter usr name and password on my router)
I want to leave that on so that other pc can access the internet with that account but i want to be able to make a connection through windows for my local account