Opening and extracting data from another workbook

[snb]

Sub M_snb()
  With Application.FileDialog(3)
     If .Show Then
        With GetObject(.SelectedItems(1))
          With .Sheets(1)
             sn = Array(.Cells(12, 2), Cells(11, 8), .Cells(16, 4), .Cells(7, 44), .Cells(77, 4), .Cells(77, 5), .Cells(77, 6))
          end with
          .Close 0
        End With
     End If
   End With
   
   c00 = Join([transpose(char(65 + row(1:25)))], "")
   Do
     y = InputBox("column", "Column letter", "A")
   Loop Until InStr(c00, y)
   
   ActiveSheet.Cells(6, InStr(c00, y)).Resize(4) = Application.Transpose(Array(sn(0), sn(1), sn(2), sn(3)))
   ActiveSheet.Cells(23, InStr(c00, y)).Resize(3) = Application.Transpose(Array(sn(4, sn(5), sn(6))))
End Sub