Paint.NET :: Any Way To Shift Pixels By A Specified Amount?

Often, especially when I'm working with screenshots, I'd like to be able to set the canvas size, and then paste in a larger image and move it to a specific point. This would allow me to automatically cut out the Windows portion of the screenshot, menu bars, scroll bars, whatever, while still keeping the actually interesting pixels in the same place from screenshot to screenshot.

In the past, what I've done is essentially to create a selection mask:

Prep:
Paste the image into the backgroundCreate a 2nd layerSelect over the interesting pixels on the image in the 2nd layerInvert the selection in the 2nd layer and fill it with a solid colorRepeat:

Make a magic wand selection of the un-colored pixels in the 2nd layerSwitch to the background and copy the selection to the clipboardWork with the copied pixels (in another Paint.Net window, or another program)

Paste the next image into the backgroundSwitch to the 2nd layerBecause of the manner in which Paint.Net handles the canvas, this workflow would be greatly simplified if I could programmatically move pixels:

Prep:
Select the interesting pixels in the first imageCrop to SelectionRepeat:

Work with the pixels remaining on the canvasPaste the next image (select "Keep Canvas Size")Shift Pixels so that the interesting portion of the image is on the canvasI looked through the entire menu structure in 3.5.10 several times, and didn't see anything that would obviously produce this transformation. I'm aware of the Ctrl+<arrow> method for moving by 10px, which is certainly better than just using the arrow keys. And I've seen references to the Panelling effect plugin which performs a similar function, but (without having tried it) I expect it would not produce the desired effect if I wanted to create negative/empty space on one or two sides of the shifted pixels, or if one of my images was smaller than the total desired area.

Is this already available in Paint.Net, and I just missed it? Or is there a plugin that accomplishes this specific transformation without additional side effects?