Is your window really moving? This shouldn't affect the positioning of the drawing relative to the window.
It's more likely that you mean that your view is moving. Are you moving the view, the sprite, or both?
If you want to draw at the same place as the top left of the sprite, you can use the same coordinate as the sprite (assuming you still have its origin at the top-left).
If you want to draw at the top-left of the window, you can know what the coordinate should be or you could use one of these two things:
sf::Vector2f topLeftOfWindow = window.getView().center - window.getView().width / 2.f;
sf::Vector2f topLeftOfWindow = window.mapPixelToCoords(sf::Vector2i(0, 0));
You may find the
tutorial on views useful