You can copy a column using the Data Mover command-line interface by specifying the value table_columns when a table is selected.
<database selection="unselected"> <name>dmguest</name> <table selection="included"> <name>table1</name> <target_name>NewTable1</target_name> <table_columns> <name>column1</name> <target_name>targetColumn1</target_name> <type>varchar</type> <target_type>string</target_type> </table_columns> </table> </database>