Dim AllCells As Range, rCell As Range
Dim NoDupes As New Collection

        Set AllCells = .Range("A1:A" & .Cells(Rows.Count, 1).End(xlUp).Row)
    End With

    On Error Resume Next
    For Each rCell In AllCells
        NoDupes.Add rCell.Value, CStr(rCell.Value)
    Next rCell
    On Error GoTo 0
    For Each Item In NoDupes
        UserForm1.country.AddItem Item
    Next Item

-- далее таким способом я вставляю выбранное значение из списка combobox
ActiveCell.Offset(0, 10).Value = Me.country.Value