Doa Vo, thanks for the reply.
With "automatic exchange" I mean:
"At the end of the turn, if a player has in his prison a type of piece already present in the opponent's prison (rook and rook; bishop and bishop; guard and guard; or queen and queen), the prisoners' exchange is mandatory: the white piece in the black prison is moved to the white reserve, the black piece in the white prison is moved to the black reserve."
This process is mandatory at the end of the turn, so I would like that a dummy player could do that. That is, the players don't exchange the hostages, the AI do that for them.
Sorry for my English. :-)