Public Declare Function SendMessage Lib "USER32" Alias "SendMessageA" _
    (ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Long) As Long
Public Declare Function GetDialogBaseUnits Lib "USER32" () As Long
Public Const LB_SETTABSTOPS = &H192

' Make this a Public Subprocedure of the Global Module
' Note that we're dealing with Option Base 1 -- which may change
Sub SetTabStops(lListWindowHandle As ListBox, iNoTabStops As Integer, lTabPositions() As Long)
    Dim iIndex As Integer' Index into array of tab stops
    Dim lDialogBaseUnits As Long' Dialog base units
    Dim iDialogUnitsX As Integer' Horizontal dialog base units
    ' Obtain the dialog base units
    lDialogBaseUnits = GetDialogBaseUnits()
    iDialogUnitsX = (lDialogBaseUnits And &HFFFF&) \ 4
    ' Calculate the "required" tab positions
    ReDim lTabPos(1 To iNoTabStops) As Long
    For iIndex = 1 To iNoTabStops
        lTabPos(iIndex) = lTabPositions(iIndex) * iDialogUnitsX * 2
    Next iIndex

    ' Set the required tab positions in the list box,
    ' by calling the "SendMessage" api and passing the
    ' handle of the listbox and details of the number of
    ' tabs and their positions.
    Call SendMessage(lListWindowHandle.hWnd, LB_SETTABSTOPS, CLng(iNoTabStops), lTabPos(1))
End Sub