Cable moden to DSL router

I recently changed providers and was issued with a have a cable modem (Scientific Atlanta (EPC2100R2 Series).

I have an old ADSL wireless router (Zyxel 4 port wireless router -Prestige 660HW-61 over POTS). My question is,can I connect the new Scientific Atlanta cable modem into the Zyxel router? The cable modem only has ethernet and USB connection and the router only accepts a RJ12 telephone jack. Is it just a matter of getting a connecting cable from ethernet to RJ12? or more complicated than that. Thanks