If this paper size can be accomodated by your printer as a custom size, Access would see it and would allow you to use Page Setup (on the report ribbon) as the way to control the size. Otherwise you would have to figure out some things on your own.
You can certainly set the width of a report or form using a length unit called "twips" - 1440 twips per inch. Remember that you set the width of a form for all sections but you set the height on a section by section basis. The question would then be whether you can print it.
I looked up the "standard" paper sizes and that isn't one of them. It isn't A0, A1, ... A6, or A7. So it might be tricky.
As to the "printing on specific parts" - you can adjust controls in increments of 1/1440th of an inch. It will be a matter of aligning everything.
You adjust controls based on their Left and Top margins plus their Width and Length. You adjust report sections by their Width and Height. Note that no section width can exceed the given page limits as set by Page Size options.