Changing the defualt name in Contacts

It is possible to change the name in contacts? for example i put my firstname (ALVIN JAY) and my lastname(BANACIA) in my nicknames (AJ) in the contacts automatically generate to the top of contacts is ALVIN JAY BANACIA in my client she wants to change the defualt instead ALVIN JAY BANACIA she wants to see the nickname (ex. AJ BANACIA) instead the firstname without changing the firstname. it is possible?