Supprimer les doublons dans le ComboBox et ignorer les cellules masquées

Private Sub UserForm_Initialize()
Set Dico = CreateObject("Scripting.Dictionary")
With Sheets("Feuil2")
    For Each c In .Range(.[E3], .Cells(.Rows.Count, 5).End(xlUp))
        If Not Dico.exists(c.Value) Then
        If c.Rows.Hidden = False And c.Value <> "" Then Dico.Add c.Value, c.Value
        End If
    Next c
   ' ComboBox1.Clear
    ComboBox1.List = Dico.items
End With
End Sub

'Déclaration de la fonction pour le masquage du bouton de fermeture sur l'UserForm
'----------------------------------------------------------------------------------
Option Explicit

Private Declare Function GetWindowLongA Lib "user32" _
(ByVal hWnd As Long, ByVal nIndex As Long) As Long

Private Declare Function SetWindowLongA Lib "user32" _
(ByVal hWnd As Long, ByVal nIndex As Long, _
ByVal dwNewLong As Long) As Long

Private Declare Function FindWindowA Lib "user32" _
(ByVal lpClassName As String, ByVal lpWindowName As String) As Long

'Variable qui va nous servir à Masquer le bouton de fermeture.
Dim hWnd As Long

'Macro qui rapporte la liste des dates et les transpose dans le ComboBox "Par_Date"
Private Sub UserForm_Initialize()
'Raffraichir pendant le code
  Application.ScreenUpdating = True
'Masquer le bouton de fermeture dès l'ouverture de l'UserForm
  hWnd = FindWindowA("Thunder" & IIf(Application.Version Like "8*", _
  "X", "D") & "Frame", Me.Caption)
  SetWindowLongA hWnd, -16, GetWindowLongA(hWnd, -16) And &HFFF7FFFF
'Curseur sur le ComboBox "Par_Date"
  ComboBox1.SetFocus
'Transposer les dates dans le Combobox et faire le tri
  Set f = Sheets("feuil2")
  Set mondico = CreateObject("Scripting.Dictionary")
  a = f.Range("e3:e" & f.[e65000].End(xlUp).Row).SpecialCells(xlCellTypeVisible) ' tableau a(n,1) pour rapidité
  For i = LBound(a) To UBound(a)
    If a(i, 1) <> "" Then mondico(a(i, 1)) = ""
  Next i
  temp = mondico.keys
  Tri temp, LBound(temp), UBound(temp)
  Me.ComboBox1.List = temp
End Sub

Sub Tri(a, gauc, droi) ' Quick sort
  ref = a((gauc + droi) \ 2)
  g = gauc: d = droi
  Do
     Do While a(g) < ref: g = g + 1: Loop
     Do While ref < a(d): d = d - 1: Loop
     If g <= d Then
        temp = a(g): a(g) = a(d): a(d) = temp
        g = g + 1: d = d - 1
     End If
   Loop While g <= d
   If g < droi Then Call Tri(a, g, droi)
   If gauc < d Then Call Tri(a, gauc, d)
End Sub

Private Sub CommandButton1_Click()
Unload UserForm1
End Sub