If I want to position the window so that it's left side is next to the left side of the screen and it takes 95% of the screen area, I use this macro:
However if I want to the window right age correspond to the right edge of the screen and still take 95% of the screen area changing the Left to Right does not work. How can I accomplish this?
The first line is where the left edge of your window will be. You want that left edge to be "moved in by 5% of the main display's width", so try:
SCREENVISIBLE(Main, Left) + SCREENVISIBLE(Main, Width) * 5%
...and because your window starts at 5% across and extends 95%, the right edge should be flush with the right edge of your display.