Timesheets and accruing Rostered days off

I complete timesheets here for employees whereby all of their 40 hours worked is allocated to a job number. When it comes to processing their wages, the timesheet comes across as 40 hours (all allocated to jobs), so I deduct 2 hours as a dollar figure (RDO deduction)from their wage and have automatic 2 hour accural entitlement. With STP2 coming in, I am unable to give this deduction a category. Any idea's on how I can remedy this?