This example adds an index at the end of the active document.
Set MyRange = _
ActiveDocument.Range(Start:=ActiveDocument.Content.End - 1, _
End:=ActiveDocument.Content.End - 1)
ActiveDocument.Indexes.Add Range:=MyRange, NumberOfColumns:=1, _
HeadingSeparator:=False
This example inserts an index entry for the selected text.
If Selection.Type = wdSelectionNormal Then
ActiveDocument.Indexes.MarkEntry Range:=Selection.Range, _
Entry:=Selection.Range.Text
End If