Int 21 Fn 5F85  - Lantastic - Change Password                              [N]

   AX = 5F85h
   ES:DI -> buffer containing "\\machine\oldpassword" 00h "newpassword"00h

Return: CF clear if successful
   CF set on error
       AX = error code

Notes: must be logged into the named machine
   this function is illegal for group accounts