found it
Command: (vlax-dump-object (vlax-get-property (vlax-get-property
(vlax-get-property(vlax-get-property wa 'ActiveDocument)'sections) 'First)
'Headers))
; HeadersFooters: nil
; Property values:
; Application (RO) = #<VLA-OBJECT _Application 0000000021ef4af8>
; Count (RO) = 3
; Creator (RO) = 1297307460
; Parent (RO) = #<VLA-OBJECT Section 00000000381311e8>
; _NewEnum (RO) = #<IUnknown 0000000033591a20>
T
now how to get the text inside the header?