Sub Demo()
Dim data() As String
Dim rng1 As Range
Dim rng2 As Range
Dim rw As Long
Dim cl As Range
Set rng1 = Range("NameForComboColumn0")
Set rng2 = Range("NameForComboColumn1")
ReDim data(1 To rng1.Rows.Count, 2)
For Each cl In rng1
rw = rw + 1
data(rw, 1) = cl.Value
Next
rw = 0
For Each cl In rng2
rw = rw + 1
data(rw, 2) = cl.Value
Next
Me.Listbox1.List = data
End Sub