Receipt amount is more than transaction amount

Hi Experts,

we have one requirement, to apply receipt on transaction which is less than the transaction amount.

Eg:1) Transaction no: 123, amount is : $100, line is only one, needs to apply $120 receipt on this transaction.

2)  Transaction no: 456, amount is : $100, lines are two (each line $50), needs to apply $120 receipt on this transaction

Kindly let me know how we can achieve this requirement. Is ther any setups required for doing this requirement? else let me know work around solution.

Regards,

Jagadeesh M