While I don’t use AE (I use Sony Vegas Pro as an NLE) and thus don’t know what is possible in yours only that it is a bit different than in Vegas, the rule of thumb would be that you can simulate 3D by warping the 2D frames in space.
I.e. giving them perspective, etc. Depending on your effects, you can also layer them to give a 3D illusion like stacking cards in different positions and distances. Such as making three different PI particles and that together make up the total effect by exporting each separately and putting each on a track in AE and tweaking them in space.
In Vegas one would use 3D Alpha Track Motion on such tracks. But you’re still dealing with a 2D – flat plane with PI files; only true 3D programs can create real 3D for they use polygons and such not two dimensional pixels such as NLE).
Bottom line, this is where creativity comes in. One can fool the eye to make it look as if it was done in 3D, but it also takes some extra work and tracks.
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The above or may not be what you were asking but that’s all I can suggest.
Others may have better ideas.