Hi guys, I got a problem when trying to create a dropdown list using data from a different workbook. It works well when the data is in the same workbook. Down below is the code that gave me error 1004:

    Range(Cells(12, 3), Cells(21, 3)).Select
    formulatext = "='D:\[DATABASE_MATERIAL.xlsx]BB'!D2:D20"
    With Selection.Validation
      .Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, Operator:=xlBetween, Formula1:=formulatext
      .IgnoreBlank = True
      .InCellDropdown = True
      .ErrorTitle = "Warning"
      .ErrorMessage = "Please select data from the list!"
      .ShowError = True
    End With
What I'm trying to do with the code above is Create a dropdown list on cells C12:C21, using the data from file "DATABASE_MATERIAL.xlsx" worksheet "BB" cells "D2:D20".
Please help me with this guys, I've been googling but found nothing about this problem. Thanks' )