using the square marquee...

I need a square around a certain part of my whole image the size of 177px by 25px. I tried using the Fixed Size property but it's not working the way I need it to. How do I make a square marquee section on my image and inlarge the width without moving the whole marquee while using the arrow keys?

-Thanks!

Hold down shift and drag what you want to add. This will add what you just selected into your main selection.

Thanks!!!

-peace