If you give the shutter button a half-push the focus box changes to green (when the camera af is on letting you know af has locked on to something) you may be able to use that idea to locate the box and then move it as you need to.
The idea is based on the technique called “focus and re-compose”. Essentially as you start to look through the viewfinder, half-push the shutter button, by the time you get the camera to your eye, the af should have the box color in green.
