help with DataGrid

[s-galit]

hi,
i want to add a column to the dataGrid .
till now i create a dataGrid with 3 columns connected to dataSet and i wand
another column that wont be connected to the dataSet
is it possible??
if yes , how ? what to change in my code?
thanks in advanced

Dim DataGrid1 As New DataGrid
Dim tablestyle As New DataGridTableStyle

tablestyle.DataGrid = DataGrid1
tablestyle.MappingName = "ex"
DataGrid1.TableStyles.Add(tablestyle)
Dim columns As String() = {"first", "sec", "res"}

Dim column As String
For Each column In columns
dim columnStyle as DataGridTextBoxColumn= New
DataGridTextBoxColumn
columnStyle.HeaderText = column
columnStyle.MappingName = column
tablestyle.GridColumnStyles.Add(columnStyle)
Next

DataGrid1.DataSource = dsAdd.Tables(0)
Me.Controls.Add(DataGrid1)