What was the other DAW and is it the other DAW that's creating all those extra channels?
Is it all just in the one track in your other DAW? If it's just one single midi track/file containing all kit pieces, kick/snare/hats and so on then can you not either drag it to your desktop or export midi file from your other DAW?
Then just drag it from your desktop into a midi track in sonar (that's assigned to EZdrummer) then you have to map the notes according to EZdrummers keymap which I think is pretty close to the general midi map.
Steve