The only way to get this to work, is if the application has the ability to maximize. You can doubleclick the titlebar to maximize or use the context menu in the taskbar.
This will ensure that the entire window is placed on the screen, but if the application was not build well enough, it will still fall outside of the screen realestate.
If your graphics card is a modern NVidia or AMD one, you can enable super resolution to give you a higher desktop resolution. Alternatively, use an external monitor that has a higher resolution.
If none of these options work, contact the developer and ask them to program in scrollbars so you can at least scroll to the areas not reachable to you.