MIB, SNMP, MRTG

I’ve a new DSL modem @ home; Conceptronic C54APRA, with special ADSL2+ firmware (I’m prepared as dutch KPN is upgrading their lines). A new feature is SNMP

I use MRTG, but the standard config does not make correct statistics. Therefore I used snmpwalk and checked the MIB ..

Now I have the MIB, I need to have te mrtg.cfg, but no idea where to start. Anyone a hint?