Code to specify the index of buttons added to command bars

I have the following code to add three buttons to the "Standard" toolbar. I want to add code that specifies where the buttons get added (they default to the end of the toolbar). For example, I want the newly created "Reply Seucre" button to come after the already existing "Reply" button.

Function AddToolbarButton(Caption As String, _
toolTip As String, macroName As String, _
Optional toolbarName As String = "Standard", _
Optional FaceID As Long = 325)
Dim objBar As Office.CommandBar
Dim objButton As Office.CommandBarButton

Set objBar = ActiveExplorer.CommandBars(toolbarName)
Set objButton = objBar.Controls.Add(msoControlButton)

With objButton
.Caption = Caption
.OnAction = macroName
.TooltipText = toolTip
.FaceID = FaceID
.Style = msoButtonIconAndCaption
.BeginGroup = True
End With

End Function

Sub AddToolBarButtons()

Call AddToolbarButton("Reply Secure", "Reply Secure", "ReplySecure", , "354")
Call AddToolbarButton("Reply All Secure", "Reply All Secure", "ReplyAllSecure", , "355")
Call AddToolbarButton("Forward Secure", "Forward Secure", "ForwardSecure", , "356")

End Sub

I cannot figure out the code for determining the index for the existing button and I don't know how to assign the index property to the new button (the index property is read only).

Any help is appreciated.