I am not sure what do you mean by dynamucally created grid on that context.
If you are creating control like this way,
GridView grdView= new GridView();
grdView.DataSource=myDataSource;
You can access the GridRows by using GridViewRows Class
GridViewRows gridviewRow= grdView.SelectedRow;
Now from gridviewRow you get value of any cell for that row, You can also go with as Sunasara suggested to get value directly from a Cell.
Hope this will help you !