Is there a way to not have a backdrop image outside a window not block the light coming through that window?

I'm working on some "atmospheric" shots of a baby nursery which means I would like long, evening light coming through the window. However, the client also wants a backdrop image of their view also in the scene, which blocks this light.

I know that some rendering programs let you identify certain geometry or materials to not cast a shadow. Is that possible in Enscape. Or if that's not possible, is there anyway to save the image as a transparent png to make it easier to drop in the backdrop image in post-processing?

Thanks! Diane

A planer image