MS word Macro to arrange pages

I need to combine pages to a larger page size. I have a word 2007 .docx document with page size 5.5x8.5. I need to combine the pages in it to a 11x8.5 size page in a special way as follows. If the document has 10 pages (5.5x8.5), then the first page (11x8.5)should print pages 1 and 6, the second page should be 2 and 7, 3rd would be 3 and 8 etc., If the document has odd number of pages(say 11), then the first page should be 1 and 7, second page should be 2 and 8, 3rd page would be 3 and 9, next 4 and 10, next 5 and 11, next 6 and 12(empty). The document contains text and pictures and tables. The document is in Docx format ( 2007 word format). Bonus : if you can make a command level program that can convert all the documents in a folder at a stretch.