Here is what I did in a simple form to do what you want:
- Create a integer global variable named incNumber
- On the PressTalk Before of the N-up object, add the following line of code: &incNumber := &incNumber+1
- On your Virtual form page that will be called by the N-up object, show the global variable into a custom data selection as this: =inttostr(&incNumber)
Then you simply need to add the code that will reset your global variable
&incNumber to 1 when you reach 70 pages.
Hope that help and it is clear enough.