Make a 3/4" wide wall to serve as the face frame. Add the windows ( turn off the transom feature and configure the frame and sash)
The cool thing about the cabinet placed behind the wall is that you just assign it the number of shelves you need and adjust it to the same height as the windows. If you don't need the wall/face frame, you can adjust it's length so it wont show up (windows will still be there), SEO or what ever.
I use this combo of window/bookcase/wall for face frame for lots of custom cabinet projects. I like the way they are adjustable in 3D window vs trying to configure it all in a single object that might do the same thing if you fussed with it long enough.