assigning an audio track to a midi track?

ok. so I've cloned my midi drum tracks 4 times to separate the instruments. I would like to export each individual track but it only will export the main audio track of each folder not each individual midi track. So I thought I would try to assign a new audio track to each midi track to see if I can export each one that way but I can't figure it out. Any help would be greatly appreciated! Thanks.

Here is a general technique that might apply to you.  (As Brian says, we need a bit more info.)

In my case, I often have an external synth—same applies to drum machines or keyboards with drum sounds—coming in on stereo audio inputs.  So, for example, a sampler may be playing 5 different instruments or drums from 5 MIDI tracks all coming in on the same audio track.

One thing you can do: 1-clone the audio track.  Now you have 5 audio tracks all receiving the same input. 2-arm one audio track and mute all but one MIDI track. 3-Hit record and the audio track will capture the output of the single MIDI track. 4-Now move on to the second audio track.  Arm it, mute everything but the second MIDI track, and hit record.  5- Repeat for the other tracks.

If you are using a virtual instrument like Session Drummer 3, the procedure is different and easier.  What I wrote applies to an external source.  Of course, if your source instrument has individual audio outputs for each drum (like an old Linn Drum), then you can record everything at once (if you want) by assigning an audio track to receive each input—but it doesn't sound like that's your situation.
 
Recording one source at a time is slow, but it ensures you get your level and sound exactly like you want, and prevents unintentionally mixing signals on a track (for example, recording kick on the kick track and both kick and hi-hat on the hi-hat track).

Let us know if this helps or if your situation is different.