VBA ComboBox filtern

Private Sub ComboBox1_Change()
Dim i As Long
Dim j As Long
Dim a As Long
ListBox1.Clear
a = Len(ComboBox1)
For i = 1 To ZZFFF3.UsedRange.Rows.Count
For j = 1 To Len(ZZFFF3.Cells(i, 2)) - a + 1
If UCase(Mid(ZZFFF3.Cells(i, 2), j, a)) = UCase(ComboBox1) Then
ListBox1.AddItem (ZZFFF3.Cells(i, 2))
Exit For
End If
Next j
Next i
Dim AAAZ As Long
If ComboBox1.Value  "" Then
AAAZ = CDbl(ZZFFF3.Range("B2:B5002").Cells.Find(What:=ComboBox1.Value, lookat:=xlWhole).Row)
End If
Exit Sub
ComboBox1.SetFocus
End Sub

Private Sub UserForm_Initialize()
ZZFFF3.Activate
With ZZFFF3
ComboBox1.RowSource = .Range(.Cells(2, 2), .Cells(.Cells(Rows.Count, 2).End(xlUp).Row, 2)). _
Address(External:=True)
End With
ZZFFF3.Activate
With ZZFFF3
ComboBox2.RowSource = .Range(.Cells(2, 3), .Cells(.Cells(Rows.Count, 3).End(xlUp).Row, 3)). _
Address(External:=True)
End With
ZZFFF3.Activate
With ZZFFF3
ComboBox3.RowSource = .Range(.Cells(2, 6), .Cells(.Cells(Rows.Count, 6).End(xlUp).Row, 6)). _
Address(External:=True)
End With
ZZFFF3.Activate
With ZZFFF3
ComboBox4.RowSource = .Range(.Cells(2, 8), .Cells(.Cells(Rows.Count, 8).End(xlUp).Row, 8)). _
Address(External:=True)
End With
End Sub