Here is a command which will create a simple window based on selecting 2 points on an opening which has been created in the facade of building.
The UCS should be oriented parallel to the face of the building. Then you would select the lower left corner followed by the upper right corner. The window is then created automatically.
The window command creates 2 layers for the window frame and glass, and places those objects on those layers automatically. In the above illustration, I've recessed the objects by moving them after the fact to improve the illustration.
You can download the Lisp routine here.
Or use the following URL: http://www.mediafire.com/download/pav98m98q418r9q/Window.lsp
Have a good one, cheers