How to output an image from the sequencer to the compositor for further processing and saving the animation?
I have a set of samples from several clips. I need to access them through the Compositor.
Blender normally goes from render to compositor to sequencer. You can either save a sequence of stills and feed them into the compositor, or create a new scene, and select the first scene as the render layer for the second.
Ah, somewhere my reply got garbled, (along with my understanding) 
What I was trying to say, is to do the compositing in a new scene with the sequences you already have, and then add the new scene strip back into the existing scene/sequence.
Load them into the compositor from the hard drive, not from the sequencer.
The question was how to get access from the sequencer. That is, the blender cannot use a sequencer in the composer.
I’ll go to DaVince.
That is correct. It can’t.