Manual focusing with a camera dial - canon R7

[joaodpontes]

Hello, I am using a canon R7 with a canon RF 35mm F1.8 Macro IS STM for underwater photography. However, with my housing I can't do manual focus because I can't touch the lens focus ring nor the touch screen to choose where to focus as well. I was wondering if it would be possible to assign one of the 3 camera dials to work like a focus ring, but can't find any info about it online. Has anyone done this before? Thank you!

[p4pictures]

I've checked the settings and it is not possible to use one of the three dials to adjust focus. 

If your housing gives a button for the AF point selection button, then it is possible to move the AF point location by pressing the AF-selection button then turning the main and quick controls dials. Main dial moves the AF point left/right and the quick control dial will move it up/down. 

[joaodpontes]

That works! Thank you much!