Hi Roys,
Sorry to say, what you are looking for, can not be achieved with the Export pdf subscription. Exporting selective pdf pages from multi page pdf file is something that is not supported with Export PDF service.
Using "Extract PDF" feature under "Organize Pages" tool of Acrobat DC application can help you exporting the selective pages to other file format. Rotate, move, delete, and renumber PDF pages in Adobe Acrobat
But for that you need to upgrade your plan to Acrobat DC subscription- Plans and pricing | Adobe Acrobat DC
Hope this helps.
Regards,
Akanchha