Hello Excel Forum

I have a worksheet with the following information:
Column A: List of employees
Column B: Supervisor of the employee

Each employee has a supervisor and this supervisor also has a supervisor etc etc until we reach the CEO who obviously has no supervisor. What i want is to make an organizational hierarchy.

Fx.

Name: Supervisor

Thomas Christian
Peter Thomas
John
Christian John


This hierarchy must then be: Peter, Thomas, Christian, John (with John as the top-man).

I have about 1000 employees and therefore i need to automatize this proces. I can't get a good idea from my head. Any help would be much appreciated!

Thank you in advance!

Hremehre