You're confusing me too now.
If the D-Link is a combined Modem/Router, you connect that to the ADSL enabled phone line in the normal way. If there is a Router/Bridge option, leave it as a Router. You run the PPPoA connection in this router.
Then, connect a "Cable/DSL" router (i.e. a stand-alone router with no integral Modem) to it by running an ethernet cable from one of the D-Link's LAN ports to the Cable/DSL router's WAN port. This router is configured for a "direct" connection or to get its IP address by DHCP. The exact terminology varies. This second router doesn't establish a connection to the ISP, that's already been done by the D-Link router.
Both routers have DHCP enabled and the second router's WAN address is the one allocated by the first router. The second router then has the computers connected to it and allocates their IP addresses.
...not sure what having the two routers achieves, but that's another matter. I do on occasions run a "sub-router" connected to my main router.