adding items to a combo box depending upon the value given

Question

I have a unbound datadridview named dgv_add, which contains columns of type datagridviewcolumn types and the another column of type datagridviewcombobox type. I want to add specific items from a database depending upon the inputted text in the column of 1st type. I mean I want to retrieve specific column from a database and add the available items to the combobox after inputting text in the column of 1st type.
eg:
DGV_Add-> datagridview
Mdcn_Name->datagridviewcolumn
Mdcn_Pack->datagridviewcombobox

PLZ HELP.

Thanks In advance.