property Column.Expanded as Boolean
Expands or collapses the column.

   Boolean A Boolean expression that specifies whether the column is expanded / collapsed.   
By default, the Expanded property is True. Use the Expanded property to programmatically expand/collapse the columns. For instance, the Expanded property on False, collapse the column, while the Expanded property on True, expands the columns indicated by the ExpandColumns property. The ExpandColumns property specifies the columns to be shown/hidden when a column is expanded or collapsed. The DisplayExpandButton property indicates whether the +/- expanding/collapsing button is shown in the column's header.