How to lock mouse cursor to monitor? (Windows 10, Dual monitors)

I have been trying to use Display Fusion and Borderless Gaming apps to lock my mouse cursor to my DDO window (and prevent it from going to my other monitor), but have not been having any luck. Although this feature works fine in other games, it just gets outright ignored when I'm running DDO in fullscreen windowed mode.

Is there an in-built "window mouse lock" feature that I am overlooking? If not, can anyone recommend a third-party program that works to accomplish this?