Private Sub Form_Load()
    Dim lNum As Long
    Dim lZeros As Long
    lNum = 20
    lZeros = 10
    Debug.Print Right$(String(lZeros, "0") & lNum, lZeros)
End Sub

Option Explicit

Dim cCombo As New Collection

Private Sub Form_Load()

    Dim i As Long
    For i = 0 To 10
        Combo1.AddItem "item " & i: cCombo.Add "Real Val " & i
    Next
    
End Sub

Private Sub Combo1_Click()
    MsgBox cCombo.Item(Combo1.ListIndex + 1)
End Sub