With the classic version of Interface Customization module, you can add existing fields to various views and grids in the interface of Store Commander.
Here is the procedure, quick and simple, to add a field in a view.
From the left handside column, choose the grid from the drop down menu and select the view you'd like to customize.
The fields already included in the view are listed in the central column.
From the right handside column, all fields you can add in the selected view are displayed.
Select the field you wish to add and drag/drop it in the central column.
Note that you can select multiple fields before dragging/dropping them.
That's it, done :)