OIE Per Diem Deduction

 Hi  Team,

We are paying per diem for abroad and local  rate base on grade of employee.

Ex : Grade 10 - 13 paid - per day $ 300

We have condition in per diem policy if employee stay long period on business trip then company will deduction the per diem allowance as follow,

Period                  Payable Allowance

-----------                ----------------------------  

first 30 day            Full - paid

Next 3 month         70%

thereafter                60%

Please advise how we can setup in single per diem policy.

Thanks