How to set laptop screen to 4:9 native, without it automatically stretching it to widescreen (windows 7)?

Tried changing screen resolution to 1280 by 768 but it streches it to the edges of the laptop screen, wanting it for battle for middle earth (which is a 4:9 game), usually i put laptop to TV and put it to 4:9, but im out on the go and playing the game on the laptop, and tbh the game looks crap when stretched, so basically how can i put the laptop screen to 4:9 native, without it automatically streching the display (im wanting the black lines to show), Thanks