Section 2106. Affirmation of truth of statement by attorney, physician, osteopath or dentist

The statement of an attorney admitted to  practice
  in  the  courts  of  the state, or of a physician, osteopath or dentist,
  authorized by law to practice in the state, who is not  a  party  to  an
  action,  when  subscribed  and  affirmed  by  him  to  be true under the
  penalties of perjury, may be served or filed in the action  in  lieu  of
  and with the same force and effect as an affidavit.