Specific elements for export/import.
| Name | Type | Multiplicity | Description | 
|---|---|---|---|
| expression | property ExpressionType | [0,1] | Expression to be used to produce value for the column. | 
Flags: RAM,runtime
Multiplicity: [0,1]
Display order:
                            Expression to be used to produce value for the column.
                         
                            Column expressions are EXPERIMENTAL. They work only under a very
                            specific circumstances.