Odpovím si tedy sám, pro český CAD funguje tato procedůra:

Private Sub VlozitXref()
Dim BT As Long
BT = Application.ActiveDocument.GetVariable("BINDTYPE")
Application.ActiveDocument.SetVariable "BINDTYPE", 1
ThisDrawing.SendCommand "-xref v * " & vbCr
Application.ActiveDocument.SetVariable "BINDTYPE", BT
End Sub

zkuste něco jako:

Function GetXRefs() As Collection Dim ThisBlock As AcadBlock Dim ThisObject As AcadEntity Dim AnXRef As AcadExternalReference Dim Result As New Collection Dim i As Integer For Each ThisBlock In ThisDrawing.Blocks  For Each ThisObject In ThisBlock   If TypeOf ThisObject Is AcadExternalReference Then    Set AnXRef = ThisObject    Result.Add AnXRef, CStr(i)    i = i + 1   End If  Next ThisObject Next ThisBlock Set GetXRefs = Result Set Result = Nothing End Function