批量修改Excel文件中'AAA'对应单元格的值为100

Sub replace()
    Dim myDialog As FileDialog, oFile As Object
    Dim FSO, myFolder As Object, myFiles As Object
    Dim fn$, cnn As Object, m&, SQL$
    Set FSO = CreateObject("Scripting.FileSystemObject")
    Set myDialog = Application.FileDialog(msoFileDialogFolderPicker)
    With myDialog
        If .Show <> -1 Then Exit Sub
        Set myFolder = FSO.GetFolder(.InitialFileName)
        Set myFiles = myFolder.Files
        For Each oFile In myFiles
            If oFile.Name <> ThisWorkbook.Name Then
                m = m + 1
                If m = 1 Then
                    Set cnn = CreateObject("adodb.connection")
                    cnn.Open "Provider=Microsoft.Jet.OLEDB.4.0;Extended Properties=Excel 8.0;Data Source=" & oFile
                    SQL = "update [Sheet1$] set 单价=100 where 名称='AAA'"
                Else
                    SQL = "update [Excel 8.0;Database=" & oFile & "].[Sheet1$] set 单价=100 where 名称='AAA'"
                End If
                cnn.Execute SQL
            End If
        Next
        If m > 0 Then
            MsgBox "文件处理完成"
            cnn.Close
            Set cnn = Nothing
        Else