inserting a page break after each 9th page? or skip print on the 10th page ?

[vender]

Hi,



I received a document made with mail merge , that has some contracts that end up on 9 pages each and i need to print them on both sides, so if i do that the the 5th page on the back gets the first page of the second contract. The document has 1.800 some pages, so doing a page break manually every 10th page will take to much time

So basically i want to find a way to print the entire document but to have the 5th page of the back side blank and the 10th page to start to print on a new page and page 11 on the back ..and so on...