My boss’s daughter as a trainee?

You work as an executive assistant in a prestigious company where graduates like to start their career. The hiring is arranged by the recruitment department and currently a position as a trainee is vacant.
Now imagine that one of the board members orders you to withdraw

the vacancy because his daughter will take the trainee position. You are aware that this situation occurred before but is also beyond all regular procedures. What do you do?

Advice
It is important first to consider which considerations are at stake. Who will lose its face if you bring this up? Who can appeal to the most significant interests? Is it the board member because he is an executive or is it the daughter who wants to make a good start in her career? Or is it the recruitment department who was overruled before? Is the company policy still clear? Does granting the traineeship to the daughter create precedents for other board members?
In your role as an assistant you best consider all these interests and review the consequences of this situation. Your challenge lies in sharing your point of view with your boss. You can show him in confidence the consequences of his proposal and point out the importance of your boss acting as a role model. Furthermore there is an option to come to a compromise: the daughter follows the application procedure and gets a fair chance.