Okay each scenario has its own VP file which can be edited using notepad. For example if you want to change a VP for the 1936 scenario open the file "......Paradox Interactive\Doomsday\scenarios\1936\vp.inc" and edit it. In the same way edit the appropriate files for other scenarios. Now when you'll start the scenario the vp change will be made.
However the above method won't work for save games which have to be individually edited to make VP changes.
P.S Although I play HOI2-DD however i'm sure same would be the case for ARMA.