That is not possible, Minecraft creates a texture atlas. You'd have to use bypass that system for .obj models.
Which isn't a good thing to do for blocks/items. (I don't think it would even be possible)
You can do it for TESRs/entities however, but you'll either have to either redo the uv in the baked .obj model,
or handle the loading on your own.
Edit: I just now realized how dead this forum is.. I am surprised that the first page still contains posts from... a few months ago)