Need help with drop shadows...

Hey folks:

I have a scene where I need my character drop shadows to “pop on” at a particular point in my scene. How do I do that? I looked under the shadow effect properties, but that doesn’t seen to be the place to make such an adjustment.
???

As far as I know, the Drop Shadow Effect cant be animated…

Workaround:
Duplicate your animated character and apply the drop-shadow…
then delete the frames where you don’t want to see the effect…

Regards
Nolan