An employee is rejoining our company 1 month after his resignation - appointment or rejoining letter?

An employee is rejoining our company 1 month after his resignation. Can anybody advise whether we should give him a new appointment letter or issue him some kind of a rejoining letter?

Dear Kabeer Sharma ji,
Have you settled the legal dues of him in full and final?
It is advisable to take him as new joinee. However, you need to complete his joining formalities as you are doing in other cases in normal course. Hope you do it.
Take is application for employment.
Interview him. Record the same.
Issue him fresh appointment letter giving reference of his application and subsequent interview.

Dear Friend,
Lot of implications hence better to consider him as a new employee.
Regards
Kamesh