It would appear that in order to simulate window light, you need to… build a window. That’s what I did, just cutting a rectangular hole in a large sheet of background paper and placing it in front of a white wall illuminated by two Elinchrom strobes.

This “window” was placed in a corner of the room. The following are a couple of (edited) examples shot with this light only, distant about 6m from the subject and a little less than 2m at the right of the camera.

Both were photographed with a Fujichrome X-T1 camera and an AI-S Nikkor 50/1.2 lens.

How the window was made: some paper background (I had a red color at hand), held at the top and at the bottom by two halves of a Manfrotto 2 Section Background Paper Counterweight, attached to a stand by means of a Manfrotto Spring Clamp.