Hello,
I think there are Praat scripts that will do what you describe, and generate an annex file reporting the corresponding timecodes. However, I don’t know exactly how you would integrate that within PennController, or any other experiemental software for the matter.
If your goal is simply to skip any silence at the beginning of your audio files, you’d be better off using a script that automatically truncate your audio streams at the beginning and at the end.
Jeremy