Hi pixelglitch,
Unfortunately, there isn't any settings available which would drag the mouse to the last used program. Yes, there is a setting which will automatically move the pointer to the default button in a dialog box. Press and hold the Windows key and press 'R' key to open the run window. Type 'main.cpl' without the parenthesis, click 'Ok' -> click Pointer Options -> uncheck the box (as shown in the screenshot), see if that helps.
Inspiron 15R is available in different variants. Please share the exact system model and the operating system installed on your computer; will take it further.