Cell-level module : keep the initial dimension of the module and position of the cells

[EstrelaStern]

Hello,

I'm trying to create a cell-level module, but the software recalculates the length and the width of my module according to the dimensions of the cells, the gap between the cells etc. and seems to consider the cells as the border of the module.
Is there a way to indicate the distance between the module's borders and the cells ; and to keep the initial dimension of the module ?

Thanks in advance.