I am not aware of any such device. We cut and paste or use PhotoShop.

I see your baseboard heat. Is it electric? If so, panels would be a fire hazard.

Do you need drapes . This is anoffice how much privacy do you need . I think the window is nice as it. I agree if that is electric heat no drapes . BTW I hate fake drapery panels you still need to buy 2.5 x the size of the rop even if you never close them. As for seeing what they look like I agree Photoshop ,

The baseboard is not electric but I really don’t think I will do drapes. I don’t need privacy there. I just was thinking a cornice or something to soften and add color.

Have you considered lace curtains on an inside-mounted rod? I think that fits well with your furnishings. I think the room would benefit from just a little something to 'stop' the eye inside rather than being drawn outside the house; I don't think a valance or cornice would do that.

I think Roman shades would look nice.