Window is vertically so long that is partially off the screen

I have a small laptop with a relatively low resolution, It often occurs to me running an app with a fixed-size window which its height is longer than my screen, like this :

Windows (OS) does not allow moving a window outside the screen from top (having negative top position) and I can not see or click buttons in bottom which are currently lied outside screen.

Anyone knows any trick/tool that enables me to see/click buttons in the buttom outside screen ?