Pick a single wire position or a range of wire positions (a range) from the list on the left. To pick a range, click on the first wire in the range, then hold the shift key down and click on the last wire in the range. Then click on the ">>>" button between the lists to move that wire or wire range to the list on the right. To remove a wire or wire range from the left list, click on it and then on the "<<<" button between the lists.