What is the opposite macro of C_ID(cell_t c,Thread*t)?
 

I'm programming an UDF that stores cell index in serial or parallel with different number of nodes.

Using the macro C_ID(cell_t c,Thread*t), I can get in parallel use the same cell index as I had in serial use.
However, when I open my case each time with different number of nodes, I have different cell ID, although the global ID obtained with C_ID is the same.

What I want to do is the opposite of the marco C_ID: given the global cell ID as an input, I want to get the cell ID of my case, which will be different depending on the number of nodes.

Thanks in advance.