Formatting numbers in a gridview

HI, I am using the following code to read an excel spreadsheet into a datagrid. The code works fine but I am left with the values showing, how can I format the results to show only 2 numbers after the decimal and the thousand seperator? (Using VB.NET) :
ColName Q1          Q2          Q3          Q4
1             123.456  45.6897 47.3587  12.5744

 Sub ReadTestData()
        Dim DBConnection = New OleDbConnection( _
                          "Provider=Microsoft.Jet.OLEDB.4.0;" & _
                          "Data Source=" & Server.MapPath("~/excel/" & "7476073472" & ".xls") & ";" & _
                          "Extended Properties=""Excel 8.0;HDR=Yes""")
        DBConnection.Open()
        Dim SQLString As String = "SELECT * FROM [Test$]"
        Dim DBCommand = New OleDbCommand(SQLString, DBConnection)
        Dim DBReader As IDataReader = DBCommand.ExecuteReader()
        GridView9.DataSource = DBReader
        GridView9.DataBind()
        DBReader.Close()
        DBConnection.Close()
    End Sub

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