Payment predictor amount or percentage

Hi All ,

In the action below, As per my knowledge PP first looks for Amount value , If the amount condition satisfies then PP generates WS-10 item ignoring the percentage value. If the amount condition is NOT satisfied then it looks for Percentage value and based on condition it applies WS-10.  So the logic is Amount or Percentage. My requirement is to generate an item WS-10 if the overpayment is 5% of am item amount but not to exceed $20. Can PP handle such conditional logic on Over or under payments?