Is it possible to select focal point when using lens blur with depthmap?

[miifanboy]

As I said in the question, is it possible to select a focal point in depthmap, lets say from 0-255, 55 is our focal point so the blur would increase going from 55 to 0 and 55 to 255. Maybe a range could be possible too, eg. from 45 to 55 is fully focused.Others would increase as they are further apart.

[NatLee]

I need to look into this further.

I have a few questions in the meantime—when you mentioned 0-255, is that a specific focus range? For example, does "55" mean that 0-55 represents the near focus, while 55-255 represents the far focus?
Additionally, would this require an (x, y) coordinate to specify the focus position and a value to define the focus radius?