How would I do that? I've never had to bother with it. I'm posting a photo of the wall above the window. Maybe that'll help.
Yeh, I can see a wall above a window. But what's that structure made from,
is it wood, brick, stone, concrete, or even steel? Because that will very much affect how you can put up a drape, like it's extremely difficult to put push pins into a steel girder or a stone block.
I know many houses in the US are of timber construction, is that what you're in?
Last time I put up drapes, I had to use masonry bolts to mount the rods, because it was brick I was fixing them to.