C# mouse emulation in inactive window?

Question

C++ / C#

How to do multiple actions in an inactive application window?

- at the coordinate 300x300 (Firefox browser) hold down the left mouse button - after a
second, move 100 pixels down;
-after another second, again move 100 pixels down and release the left mouse button.

All this happens in an inactive window, ie. with hWnd of the target window.
Coordinates are not attached to any elements inside the window, so that actions take place even on a blank page.

Answer 1

If I understand correctly, you need a drag and drop system and it's generally better to do it in JS, if this applies to the browser