How to zoom in on a specific part of an image?

Question

C++ / C#

Let's say we have a picture of a person, we need to shift the focus to the wrist, for example, that is, enlarge the picture and change the coordinates so that the wrist is in the center of the screen, I thought to do this simply by placing the picture and changing the coordinates and size with the script, something does not work. ..
I set the coordinates alone, but in the inspector they are different, the coordinates differ from the resolution, so far I don’t know how to do it - so that the script enlarges the picture so that the desired fragment is in the center, regardless of the resolution ...
And we are not talking about a smooth change, at least get the right coordinates first (or set them correctly)