i feel it little confusing

i am creating the dropdown for excel dynamically from vb.net code , so the names of the controls are not knwn
instead of populating it from vb.net code how do i populate each dropdown controls created with data from database
2) i exported some data to excel with blank dropdown
when i try to save the exported excle sheet i get error saying that the excel is corrpouted & cannot be saved

if i remove the code for dropdown i can save it properly