Query on computed value

Hi

I think the answer is no! But.....

I have a calculated property in my employee table, TILbalance, which is the "Time In Lieu" an employee has available. It is calculated from another table which tracks TIL accrued and taken. 

result = Me.TILs.Sum(Function(e) e.HoursBanked) - Me.TILs.Sum(Function(e) e.HoursTaken)

Can I create a query which allows me to find all employees with a TILbalance greater than a passed parameter (or even a fixed value)?

Thanks

Graeme