Flex Datagrid - 如何以编程方式执行多项选择（仅限列）

I have a datagrid and I'm trying to allow the user to click a button to select a specific column of my dataGrid. I'm trying to select a specific column so that that the user can then copy and paste it into excel. I'm able to selects all columns and row showing, but only want a specific coloumn. If anyone has any suggestions, that would be awesome - Thanks!I have a datagrid and I'm trying to allow the u