Starting element playback at a particular time

[Dave Mateer]

How does one add an element into a pipeline to start playback only at a particular point in time?

That is, suppose you have a video source and two audio sources. But the second audio source should start playback 1 minute into the video, perhaps even overlapping with the first audio source. How do I add the second audio source to my pipeline and set it to start 1 minute into the pipeline playback? 

A "read the manual" response is fine, but please provide the page of the manual to read. I couldn't find what I was looking for, but I might not know the media terms to describe this behavior.

Thanks!

Dave