From Xojo Documentation
| This item was deprecated in version 2019r2.
Please use ListBox.CellAlignmentOffsetAt as a replacement.
The value is the distance in points from the right edge of the cell. Row and Column are zero-based. This property overrides ColumnAlignmentOffset for that cell.
Any value specified here is applied to the value used for ColumnAlignmentOffset.
This example is applied to a column that is right-aligned and moves the contents of a cell 10 points to the left.