Recalculated Regular Rate of Pay

We pay out various production bonuses throughout the year. Because these are non-discretionary bonuses we need to go back and recalculate the regular rate of pay for over time purposes. Currently we are doing this in excel spreadsheets. Does anyone know of a way to do this inside of JDE? Each type of non-discretionary bonus covers a different time frame so the look back period would need to be variable. We also do not use the time and attendance features in JDE. We have a separate software for time and attendance and then import the hours into JDE.