does anyone have an Idea how to make volumetric light shafts
that react to overlay pictures (such as leaves on a tree)

The reason is that I am making a deep jungle scene
(a lot like the videos of crisis Ive seen on youtube)

the sun is almost directly overhead.

If you already know how I could really use some help.
Or if you just want to post ideas on how to pull this off that could help to.