أو استخدم هذا لعدم التكرار
Private Sub ComboBox1_Click()
LastRow = Cells(Rows.Count, "c").End(xlUp).Row + 1: For s = 1 To LastRow
If ComboBox1.Text = Cells(s + 1, 3).Value Then
ComboBox1.ListIndex = -1
Else: Cells(LastRow, 3).Value = ComboBox1.Text
End If: Next: ComboBox1.ListIndex = -1
End Sub