I’m sorry, this is not possible.
Only the 7 on-board preset buttons can be assigned to folders.
You can connect up to 7 external preset buttons (same action like on-board ones) to connector J9.
Thanks for your answer.
Perhaps i didn’t understand but if i assign 5 of the 7 on-board preset buttons to specific folders, i connect 5 remote push buttons to connector J9 it will work ?