Exporting data from datagrid to Excel

Question

Hi
I am trying to export data from datagrid to excel sheet. My datagrid is having 5 columns and while exporting i would like to see only 3 columns in excel sheet. How can I do that? I appreciate if any one give an idea.
Also while transfering the data from datagrid to excel, I would like display header and footer to the transferred excelsheet.
Thank you
Prasad