You could create a new frame covering the area you want, then add it and all the items below to a group and export the group.
If you are up to a bit of C++ you could look at the Snap shot utils sample plugin.
I'm not sure if that would work.
If I know that I want a preview of section A and it covers just 5% of the page for the preview option I would want a zoomed in picture of the page but also include some of the surrounding areas as well. Is something like this possible?
I know the bounds of the page and the bounds of the element. Is there a method around saying print out a section of a page with just these bounds (I should be able to calculate this).
I suggest a workflow like this:
1. dialog ask user for number of page and section coordinates (lets say left-up corner, width and height) in active doc;
2. the surrounding area size can be set there as well;
3. this dialog let user to choose some output properties including output file path;
4. entire page is exported to a temp file;
5. new doc and empty rectangle with proper size is created;
6. rectangle's stroke is as wide as surrinding area is set;
7. rectangle's stroke transparency is set to some value (another dialog entry?);
8. page as an image is loaded there and moved to proper position;
9. rectangle is exported as JPG or PNG (CS6+) according to dialog choices.
I should take 1-2 hours. How worth is it for you?