Bank Data Fast Coding Options

In regards to Accounts Receivable Payments, the only option to apply the payment is to the Customer and no further options, but in my business I receive partial payments and I need to apply it to certain invoices as per customer's remittance. As it is at the moment, the payment sits on the customers account as a credit waiting to be applied, but if we were able to apply it in the Portal then the entry will be completed, and no further work needs to be done in regards to these payments in Reckon Hosted.