Automatically load associated file into matlab GUI

We have data file in a very specific extension; say ''.nzz''.

I have associated this file format with ''MATLABGUI.exe" which an executable compiled with matlab.

Within this GUI we have a browse and load to read ''.nzz'' files.

Right now it opens the ''MATLABGUI'' window but does not load the '.nzz' file.

How can I automatically load this into the GUI when opened from explorer window?