How to import a grid file to Zemax?

Dear all,

Does anybody know how to import a grid file matrix (100x100 e.g ) from Matlab to Zemax?

So far, I have the file .grd . However, once I try to upload it on zemax "Grid Sag", then occurs an error which says "grid files must have at least 5 rows and 5 columns", which I do...

I also know that I have to use the following function from MZDDE toolbox.

(.......)

gridsagupdate = zImportExtraData (2,'newphaseMatrix.grd');

Thanks in advance,