Take a look at the Appendix XIV in vol. II of F. de Bas, "Prins Frederik der Nederland en zijn tijd," 1891:
https://books.google.com/books?id=1SzrAAAAMAAJ&pg=PA719&lpg=PA719&dq=%22Sterkte+der+Armee%22+1809+Adelborsten&source=bl&ots=nPSXoNVBKj&sig=ACfU3U08TUANysycQyJHcBGCJmx425WImw&hl=en&sa=X&ved=2ahUKEwjwy-yp0KjlAhUomuAKHeeFCagQ6AEwAHoECAEQAQ#v=onepage&q=%22Sterkte%20der%20Armee%22%201809%20Adelborsten&f=false

Note that is seems the 5th Regiment had only one battalion in 1809 (on Walcheren Island).