Need to have example.com/directory-1 and example.com/directory-2 run different versions of PHP.
Both versions are installed and working with plesk and I can switch between them and set different versions for subdomains or the entire domain but I need one directory to use an older version and everything else the newer one for backwards compatibility.
This is on windows.
That doesn't seem to make any sense from an administration angle. What would/should happen if a script from directory-1 includes a script from directory-2 (or vice versa)? There will only be 1 interpreter and you can't switch between them while a script is run. So either work with subdomains or better yet, update your legacy scripts so you that everything works with the newer version of PHP.