How in DataGrid WPF to change cell values ​​according to the first by "stretching" as it is done in excel?

Question

Database

I am making a WPF + Math.metro + EF application in which I need to change several values ​​like excel,

i.e. we select a cell, an icon appears and, having grabbed the icon, drag it down, while changing the values ​​of the cells.
I do not want to use a separate component for this, such as this one
. Who can tell me how to do this?