After the amuse last night, playing domino, drinking beer, I had woke up early, just for go to the office and help Ariel with dosemu.
The solution was simply: one system user can access to the dos root, this user have as shell the dosemu program and can't log neither ssh or console. When another user want to use the clipper app, only have to su to the user owner of the dos root. Neat!
But I had to spent almost 4 hours playing with the naisty suid... And it doesn't work!
Later work in the new page for the operating systems II... I think it'll move consciences.