请问怎样可以用vb修改文档特定行的内容呢，我只会编打开保存文档的vb程序，中间部分的不会。请高手关注，谢了

Option Explicit



Private Sub Command1_Click()

    Dim s As String

    Open "d:\1.txt" For Input As #1

    Open "d:\2.txt" For Output As #2

    Do

        Line Input #1, s

        s = Trim(s)

        If 1 = InStr(1, s, "C0000") Then

            s = modifysecond(s, "88888888")

        End If

        If 1 = InStr(1, s, "C0001") Then

            s = modifysecond(s, "99999999")

        End If

        'Debug.Print s

        Print #2, s

        

    Loop While Not EOF(1)

    Close #2

    Close #1

End Sub



Private Function modifysecond(ByVal s As String, ByVal change As String) As String

    Dim i As Long

    Dim j As Long

    i = InStr(1, s, ",")

    j = InStr(i + 1, s, ",")

    Dim ss As String

    ss = Mid(s, 1, i) & change & Mid(s, j)

    modifysecond = ss

End Function