SMART datagrid v.1 > Classes > ColumnGroup
Column object of the location of index parameter among child columns.
If index is less than 0 or greater than the number of columns being included in this Column Group, it will return undefined. It contains the columns which are not displayed now, and may be different from the displayed location.
If want to get from the columns which are not displayed, you can use getVisibleItem.
var col = group.getItem(10);
if (col && col.isVisible()) {
col.setVisible(false);
}