Is it possible to achieve this easilly with updating the sales_flat_order status info? Or is this information defined in other db tables?
You can update values using
UPDATE `sales_flat_order` SET `status` = 'Your status code here' WHERE `entity_id` = 99;
But for consistency you have to change the value of
status in the
sales_flat_order_grid table also. That one is used to display the orders grid.
But be careful. You may have to change the
state field also. The
status may depend on the
state field. Each status is allowed for one specific state.
You can check the relations between state and status from
Before changing anything I recommend a backup.