I now have a better idea of what you want to do. No need to leave Photoshop first make your selection now open the path pallet at the bottom of the pallet there is a button to press that will convert the selection to a path. Now with the path selection tool that is on the tool bar select the path now press control+T to scale the path when done click OK ,then back in the paths pallet press the button to fill with the foreground colour. That should give you what you want.