Pensionable earnings for employees on unpaid leave not counted towards pensionable service

We are using Peoplesoft for NA 9.2, image 44, Peopletools version 8.60. We have a custom integrated attendance management system and are in Canada.

The federal government pension centre allows employees to exclude from their pensionable service time spent on unpaid leave over and above the first 3 months. Employees can elect to do this to avoid having to pay back the contributions when they return to work.

Can anyone advise on best practices for keeping the pensionable earnings special accumulator accurate when employees are on long term unpaid leave, and elect to exclude the time from their pensionable service? The way we have set up Peoplesoft, employees on unpaid leave over a certain duration aren't processed by payroll at all, and so their pensionable earnings become inaccurate. This gets cleaned up manually and laboriously near year end by payroll who need to make manual adjustments to the pensionable earnings before processing T4s.