Getting current time of a composition/layer and updating effect parameter at render time

Hi,

I had my first look to the After Effects SDK recently. I want to create a plug-in that is able to get the current time of a arbitrary (pre)composition/layer and push this value to an effects parameter.

I experimented with the SDK and read through the documentation and came across two limitations so far:

1. Functions like "AEGP_GetLayerCurrentTime()" won't work at render time correctly.

2. Updating effect parameters is only possible at certain events. There seems not to be something like a "time changed" event. I was hoping with a event like this, I would be able to update a parameter when the user scrubs through time interactively or at render time.

My question is, are there any ways to work around these limitations or do I not stand a chance with my undertaking?

Many thanks,
Peter