The warp tool is wonderful, but I'm afraid it's also new with CS2.
Earlier versions of PS didn't have it; but it you have PS CS2, Haravikk, it's really easy.
You don't need to worry about the control handles, since what you want is a simple, symmetrical shape. It's in the presets.
First, you'll need to give yourself more room on your canvas, of course.
Then select your shape, and tap
Command/ctrl T to transform. When the Transform Options come up, click on the Warp icon on the far right of the Options bar, just before the Cancel, Accept, Bridge etc. buttons. (I've shown it below outlined in yellow below, although I cut out quite a bit of the bar, to save space.) That will change the whole bar to what you see here.
Choose Arch from the drop-down menu after the word "Warp." That will give you the correct shape. Click on the word "Bend" and drag right and left to interactively change the bend amount, or type the amount into the field, if you know it already.
If the bend is going the wrong way, type the minus sign before the number, to bend the other way, and then drag.
If you need a "side" bend, instead of a "top or bottom" bend, click the "filp" button just to the right of the Warp menu.
It's simple, with CS2.

Hope this helps!