datagrid - manipulate cell content

Hi,

Is it possible to change the cell contents of a datagrid?

My datagrid is filled with data from datatables. I have for instance this result:

(Customer) (order)
John chair
John phone
John table small
Erica chair
Erica table long

But I want the second and third cell (wich contain "John") empty because it is repeated.
And I want the 5th also empty

Thanks, kleedje