After some search and some help from SolidWorks support, I've completed a macro and I want to share it.
It's a macro to zoom a drawing as it would be printed, so you can preview on your screen how it would looks like on a real sheet before printing.
As Windows doesn't provide any reliable way to find physical screen size (to get PPI), I found it easier to ask the user.
This only works on the main monitor (if you have more than one monitor).
I hope it will be usefull !
SolidworksApi macros