Private Sub ListBoxFuellen(DieListbox As MSForms.ListBox, DerRange As Range)


    With DieListbox
        .ColumnCount = DerRange.Columns.Count
        .List = DerRange.Value
        .ColumnHeads = True
    End With
    
End Sub

Private Sub UserForm_Initialize()
Dim lngLetzte As Long
    With Sheets(1)
        lngLetzte = .Cells(.Rows.Count, 1).End(xlUp).Row
     
        ListBoxFuellen ListBox1, Blatt3.Range("A4:D" & lngLetzte)

    End With
End Sub