Internal table of Table Control Wizard in Screen

Hello,

I am trying to modify the internal table of existing Table Control Wizard by adding a new field to it. It already have 5 fields and m trying to add additional field to it. But I am not sure, how to add extra field in the Table Control Wizard. I cannot delete and create a new table control wizard.

Let me know if you have any idea to add field to the internal table and the table control.

Regards,

Reema