Add field on InventOnHand form

Hi there, I’m new in Axapta. I would like to add a new column on grid on InventOnHandItem form. The field that i need to show is MinInventOnHand of ReqItemTable. Any ideas on that??? I have tried to add ReqItemTable datasource on the form and make changes in relations but haven’t obtained the result needed. The problem is that we have got coverage combinations with Warehouse and Configuration; and I need to recall the `search’ function. Can anyone explain me how to add that field, and requery it depending on visualization mode on that form??? Thanks to all.

class InventDimCtrl_Frm_OnHand is responsible for creating the query for this form