Is it possible . . .

I’m not sure if this is the right forum but here goes

Is it possible to assign different patches within a midi track?

Context:

My production requires an oohs and aahs track. I created a track with Halion and recorded my aahs. So I go into the midi editor and I would like to replace some of the aahs with oohs. For any note, I can control volume, pitch and timing but can I plug a different sound into that space?
Is a dedicated oohs track the only solution?