I am looking for information on Scene 7's feature to automatically add screen fill images to images of laptops and computer monitors. The Scene 7 help URL seems to be down: http://help.adobe.com/en_US/scene7/using/index.html
Do you mean templating? Adobe Scene7 * Template Basics
This works in a similar way to a layered photoshop file, in fact you can even upload a PSD and let S7 manually create the template.
You can then control the layers via url commands e.g. to swap images