Create a sub-grid inside a box around a point moving inside the box

Hi All I would ask you if you know if there is the possibility to generate inside a 256x256x256cell fluid domain one subgrid let say wit 200 points for direction correspondin to 5 cell of the main cube, around a data point present inside the box that moving during timestep … and of course this subgrid with 200points corresponding to 5 cell of the oriinal cube interpolate the value given by the main box

Sounds highly specific.

May be doable with a ProgrammableFIlter or, of course, a C++ VTK Filter plugin.

Any Idea about Programmable Filter ? maybe just the pseudo code …
I neve used C++ VTK Filter plugin, I’m using C++ for implement models in openFoam