How do I access the internal numbering for a heading?

Which property of a paragraph is the numbering? E.g. for the 2nd Heading 1 element, this is “2.”; for the 1st Heading 2 inside it, this is “2.1.”. I can’t find this info…

Here’s my code to build a list of internal anchors:

' auxiliary sub for BuildAnchorList
Sub AddItemToAnchorList (oAnchors() as String, sTheAnchor as String, sType as String)
	Dim sAnchor
	Select Case sType
		Case "Heading":
			sAnchor = "#" + sTheAnchor + "|outline"
		Case "Table":
			sAnchor = "#" + sTheAnchor + "|table"
		Case "Text Frame":
			sAnchor = "#" + sTheAnchor + "|frame"
		Case "Image":
			sAnchor = "#" + sTheAnchor + "|graphic"
		Case "Object":
			sAnchor = "#" + sTheAnchor + "|ole"
		Case "Section":
			sAnchor = "#" + sTheAnchor + "|region"
		Case "Bookmark":
			sAnchor = "#" + sTheAnchor
	End Select
	ReDim Preserve oAnchors(UBound(oAnchors)+1) as String
	oAnchors(UBound(oAnchors)) = sAnchor
End Sub

' auxiliary sub for BuildAnchorList
Sub AddArrayToAnchorList (oAnchors() as String, oNewAnchors() as String, sType as String)
	Dim i, iStart, iStop
	iStart = LBound(oNewAnchors)
	iStop = UBound(oNewAnchors)
	If iStop < iStart then Exit Sub ' empty array, nothing to do
	For i = iStart to iStop
		AddItemToAnchorList (oAnchors, oNewAnchors(i), sType)
End Sub

Function BuildAnchorList()
	Dim oDoc as Object, oAnchors() as String
	oDoc = ThisComponent
	' get the whole document outline
	Dim oParagraphs, thisPara, oTextPortions, thisPortion
	oParagraphs = oDoc.Text.createEnumeration ' all the paragraphs
	Do While oParagraphs.hasMoreElements
		thisPara = oParagraphs.nextElement
		If thisPara.ImplementationName = "SwXParagraph" then ' is a paragraph
			If thisPara.OutlineLevel>0 Then ' is a heading
				' ***
				' *** TO DO: How do we get the numbering for each heading?
				' For example, if the first level 1 heading text is “Introduction”,
				' the correct anchor is `#1.Introduction|outline`
				' and we are recording `Introduction|outline`
				' ***
				AddItemToAnchorList (oAnchors, thisPara.String, "Heading")
			End if
		End if
	' text tables, text frames, images, objects, bookmarks and text sections
	AddArrayToAnchorList(oAnchors, oDoc.getTextTables().ElementNames, "Table")
	AddArrayToAnchorList(oAnchors, oDoc.getTextFrames().ElementNames, "Text Frame")
	AddArrayToAnchorList(oAnchors, oDoc.getGraphicObjects().ElementNames, "Image")
	AddArrayToAnchorList(oAnchors, oDoc.getEmbeddedObjects().ElementNames, "Object")
	AddArrayToAnchorList(oAnchors, oDoc.Bookmarks.ElementNames, "Bookmark")
	AddArrayToAnchorList(oAnchors, oDoc.getTextSections().ElementNames, "Section")
	BuildAnchorList = oAnchors
End Function