how do add a control to the footer

Question

here i got a senario..... i've been asked to allow scrolling on the datagrid column wise ( not row wise or paging. mind u). i thought it cane be done if we add controls to the footer of the datagrid so that each time u press the control the datasourse to be bound will be updated with new columns. if i'm not worng plz help me in this senario.