Is the following sentence ok with whichever?
Mr. Morrison would like an employee to help customers whichever one enters the restaurant (first).
Suppose Mr. Morrison was the owner of a restaurant, and none of his employees has arrived yet. It was 11:30 in the morning, and his restaurant was already full of people. He wished his employees would show up and serve the customers. It didn't matter which of his employees would show up; just anyone would do.
If punctuated as a disjunct afterthought it is grammatical and could be taken to modify employee, although the grammatical and the clear are not to be confused with one another.
Mr. Morrison would like an employee to help customers —whichever one i.e. employee enters the restaurant (first).
Merely the change of a few incidentals (but not the structure) will make the clausal relationship clear.
Mr Morrison would like an employee to welcome customers —whichever one is neatly dressed in his or her restaurant uniform and is ready to assume that responsibility.
Absent those details, it's not clear whether the clause applies to the customer or the employee.
The disjunct clause can be repositioned for clarity:
Mr. Morrison would like an employee—whichever one enters the restaurant first— to welcome customers. .
As it stands, the whichever clause applies to the customers. To make it apply to the employees, you would have to say
Mr. Morrison would like whichever employee enters the restaurant first to help the customers.
