Photoshpo Question (pre-defined selection)

[GreenMint]

Hey all, was working on photoshop the other day, thought about trying to make a few sigs for on here, then I thought of something i'd like to be able to do, but wasn't sure if it's possible..

I know to make a sign i CAN make a 400x75 picture, leave it blank, move another picture onto it, and move it around until it shows the parts i wanted to.

Is there anyway to make a pre-sized selection box (ie: selection rectangle, that is 400x75) so that I can see what part of the picture would be selected should I drop this selection box on it and copy to a new document?

Thanks

 

[GreenMint]

Typical, just went in and had another scoot round, and found how to do it, but thanks to anyone who looked!

 

[Paul_Canning]

You'd be amazed what lies within the dusty tome that is the Help File