DataGrid Flexibilty Like Excel

Question

 I have one datagrid with some data,I want to give excel like flexibilty to datagrid.Like ,supposed to I have excel file in that file when I type any value in any cell and when we drag that row with mouse press in vertical direction or horizonatl direction it get be paste that value in all row as well as column.so How can i does like this functionality in silverlight 4 in datagrid.
Please any one give me reply.I have done copy paste row of column using button.but i want like below functionality.