从外部数据导入DATAGRIDVIEW,如何从第5行开始导入？

如题，怎么设置从第3行开始导入？如下代码该怎么改正，请各位指教。

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim intColCount As Integer = 0
Dim blnFlag As Boolean = True
Dim mydt As New DataTable

    Dim mydc As DataColumn
    Dim mydr As DataRow

    Dim strpath As String = "E:\Computer Knit\PR20150611_0801.csv"
    Dim strline As String
    Dim aryline() As String

    Dim i As Integer
    Dim rowNum As Integer

    Dim mysr As System.IO.StreamReader = New System.IO.StreamReader(strpath, System.Text.Encoding.GetEncoding("GB2312"))
    strline = mysr.ReadLine()
    rowNum = 1
    While (strline <> Nothing)
        aryline = Split(strline, ",")
        If rowNum = 1 Then
            If (blnFlag = True) Then
                blnFlag = False
                intColCount = aryline.Length
                For i = 0 To aryline.Length - 1
                    mydc = New DataColumn(aryline(i))
                    mydt.Columns.Add(mydc)
                Next
            End If
        Else
            mydr = mydt.NewRow()
            For i = 0 To intColCount - 1
                mydr(i) = aryline(i)
            Next
            mydt.Rows.Add(mydr)
        End If
        strline = mysr.ReadLine()
        rowNum = rowNum + 1
    End While
    DataGridView1.DataSource = mydt
End Sub

定义变量i,存储datagridview 的行索引，循环所有行，当索引号是你所要插入的行时，开始插入，否则什么也不做