add new custom field in admin return view list

Hi, Please tell me the steps to add a new field in admin -> returns list view with sort and filter feature. (Opencart 1.5.5.1).
I added a new input in frontend return page and added a new column in database (returnChoice with values 1 or 2). Client need to tell if he wants money back or product change.

I don't know how to display that information in admin. Can you help me ?