It might not be possible for user stories, but I'm trying to show the new state that I created in the stories board.
We are using the Stories backlog board and under tfs (even through the board by clicking on the items) we can set the items to the new state.
All the info that I've found is about tasks or bugs by exporting the wit file using witadmin but I can't see any way to do the same with user stories.
Any help will be appreciated.
Regards.
You'll need to export the process configuration file for your Team Project using witadmin.exe
Import and export process configuration [witadmin]
Add in your new state in the requirements category, for example, an "In Progress" state
Then import again
Finally, go into your kanban board settings and add a column for the new state.
Some more detail here