AutoCash Rule and Receipt API

Hi all,

We are using a POS system to capture all receipts from customer and pass it through API to Oracle.   In a case where a customer puts an on-account receipt the receipt should be applied to the oldest invoice first.  The POS will not handle this, it will only take the receipt.  But once the receipt is passed through to Oracle, the requirement is to have the receipt automatically applied to the oldest invoice first.  Is there any way to achieve this? I know that the autocash rule handles the receipt application, but is it possible to include this rule in API?