A CorelDRAW user recently asked me if there was a way to create a box of an exact size with an outline on it. The most common usage of this would be to create a border around an ad. Remember that half of the outline is inside the shape and half is outside. So even if you draw a rectangle of the exact size, the outline will make it larger than what is allowed.
There is a simple answer for this, though it will take a couple of extra steps to create. Start by drawing a rectangle at the exact size you need. Now use the Contour effect to create a contour line inside of the original rectangle by the amount you want for the thickness of the border. Break apart the two objects making up the contour. Combine those two objects together. Fill the combined border with the color of your choice and remove the outline. Voila, you have a rectangle of the exact size you need with a border the exact thickness you desire.