Try this:
Record the MIDI from your DTX.
Separate it into a different MIDI track for eack piece of the DTX kit.
Send the Kick MIDI track back to the DTX and record that as an audio track.
Send the Snare MIDI track back to the DTX and record that as an audio track.
Same for each other drum.
 
It'll be more work than running the MIDI through AD, but it'll give you separate tracks for each DTX piece if that's really what you want.

This is the best video I've seen on setting up AD2 in Sonar, https://www.youtube.com/watch?v=H5lyNXUDE24
 

Is this helpful  Syncing a Drum Kit to AD2
Then follow it with the video from here ~~~> Separating AD2 Tracks in Sonar for individual drum tracks
 
Than should work for you.