How do you zoom in (animated) on a portion of your canvas?
Here's what I would do...


Create a camera
Create a null object
Set the parent of the null object to be the camera
Make the null object a '3D' object
Use the null object's properties to zoom and move the camera around, e.g. use the 'z' position to zoom


You could do this with the camera by itself, but the null object is sometimes easier to deal with. Ease in and out of the keyframes for a smooth animation. I hope this helps!