How to Calculate Payroll Cumulative Results in the Future

I need to calculate the cumulative year end total for a wage type while running payroll for the current period. Is there a function module or another way to do it?

RGDIR only has results up to 4/2016, so I cannot use PYXX_READ_PAYROLL_RESULT

Example:

The current period is 5/2016 and I am running payroll. Within a user exit during payroll run, I will calculate a wage type that is dependent on cumulative year end totals so that I can stay within a year end limit.

Requirement:

I need to calculate the cumulative Year End total for a wage type at 12/2016 (while I am running payroll for 5/2016 (within a user exit)).

How can this be achieved?

Thanks!