Hi Sourav,
I don't think there is any standard FM to achieve your outcome.
I would assume that at first step you would have list of payment lot numbers & item numbers for processing and then you would update the fields such as Business Partner, Contract Account and then posting the payment. I would suggest you to go for BDC solution where you can execute the screens sequentially and populate the details.
Let me know how you go.
Thanks,
Bodhisattwa