creating dynamic columns in telerik radgrid and accessing cells of that grid

Question

i need to create dynamic columns in rad grid and place rad comboboxes in each cell of that grid.Now after this i have to bind those comboboxes to the datatable. i have created columns and placed comboboxes in each cell but i am unable to bind datatable to those comboboxes.i used class inheriting from itemplate interface and using InstantiateIn method to create columns and placing comboboxes.
thanks in advance
Anirudh