Point in a rotated box

EDIT: NM this problem is solved.

Hi, checking if a point is inside a box (2D or 3D) is simple if the box is not rotated but what about box that is rotated around the z axis?
I have TGE so it would be great if any one happens to know if it already has function to check for this. I have tried searching but im unfamiliar with the terms.

Thanks!

- Jari.