Expense Management-Multiple Employee Authority

I want to know if it is possible to create a multiple employee authority for an employee by using Effective Dates that are in P0150.

Example: Employee X  want to give authority to employee Y to do his expense report for him.

It can be done By P09E103 (there is no effective dates in that screen), and it creates a record in F0150 with Structure Type = ERS. It can be done directly in P0150 too.

Can we go in P0150 and do a set up like Employee X give the authority to employee Y from start date 01012013 to end date = 31012013 in P0150 AND then create another line with employee X giving the authority to employee Z from start date 01022013 to 10022013 ???  It means that I want to have 2 records with structure type = ERS in F0150 but no superposition because of the dates....