Hi,
Several people have done this on the self build site, assuming you are a self build, because if you have a factory built this may fall foul of insurance by modifying your vehicle. There are no regulations or inspections on self builds beyond a double bed, table, storage, water and cooker( does no specify what type of fuel), so loads of space to do what you want outside of these areas. As for self build there are no regulations to stop you but you have many factors to consider. Vents, it was discussed using chimneys out of canal boats for you roof, but other factors of what to do while moving. Try the self build site and look at past projects they have listed. I am no longer a member because I felt they got greedy over yearly subs but if you are serious the subs may be worth it for the specific task you want to do.
You really need to provide more detail if you wish more help, are you making or designing your own wood burner or off the self, are going to use it moving etc etc!!!