Can you describe a little more what you want in the end? Right now it sounds like you want the outline of a rectangle with nothing in the inside. That can be achieved by setting the stroke to a colour and the fill to nothing, which can be accomplished in the bottom left corner of the screen (there are a row of squares of different colours plus a white one with a red X through it signaling no colour, which can be clicked on to set the fill of a selected object or shift-clicked to set the stroke, the results of which will be shown on the object and also on two other rectangles in the bottom left) or by using the window brought up by pressing the key combo Control-Shift-F.
-Arlo James Barnes