Create new window design

[ARCHIJEF2000]

Some windows can be made directly in Chief by selecting the window and modifying it through its dialog box, there are further possibilities by "gluing" two or more units together to form a block or "mulled " unit.
Other windows may need to be made as a model which is introduced by importing as a window symbol via the symbol import facility. This model can be made using various techniques in Chief, or by a third party program.
But your request is rather vague, see
http://www.chieftalk.com/showthread.php?t=33918

Try a least to post an image, even if its just a line drawing.