Provident Fund Deduction On 20,000 Or 15,000

Dear Sir/madam,
As per my opinion, my Basic+Special Allow + Exgratia is ( 12000+4000+4000)
= Rs. 20,000/- as per Judgement of Supreme court in civil Appeal No 6221 of 2011
as per maximum limit of Rs. 15,000*12% = Rs. 1800 (Employee Contribution)
I would like to know that, what is the correct formula in excel format for this rule .

If an employees' basic is Rs. 30000.00 and remain 15 days absent than PF will be deducted on Rs. 7500 or Rs. 15000.00 as per Act.
Please clarfy.
Regards
Sone Lal Kashyap