You can only toggle VRAM, DirectX etc. with command lines (see http://www.create-games.com/article.asp?id=425 - note that these command lines work with ANY MMF-built EXE).
So the easiest way would be to make a BAT file which runs your game with a command line (shortcuts use absolute paths which borks everything if you try to send it to someone else).
Alternatively you can get VRAM togglable by a menu so long as the main game is a seperate EXE. When you start the game, you'd have to launch the main game EXE (with chosen command lines) and close the menu EXE, and when the main game is over launch the menu EXE and close the game.