Loan Interest calculation based on Closing Balance

Dear Experts,

I have an issue regarding Employee Loans.

Employee takes Vehicle loan of 2,00,000 INR with interest rate of 7% for 5 years from 01.04.2013.

Monthly Repayment = 3333.33 INR starting from April-2013.

So during simulation of Payroll for April-2013,

Interest gets calculated on 2,00,000 amount which is opening balance.

And in May-2013, it gets calculated on (2,00,000-3333.33) amount, which is opening balance for May month.

Now according to client's requirement, Interest should be calculated on Closing Balance.

E.g. In April-2013, Instead of 2,00,000, interest should be calculated on (2,00,000-3333.33) &

       In May-2013, Instead of (2,00,000-3333.33), interest should be calculated on (2,00,000-3333.33-333.33)

That is, Repayment should happen first and then interest should be calculated on the balance amount.

How to achieve this? Is it possible trough standard configs?

Kindly get back.

Thanks,
Amit