LP plan based off of hours worked

Has anyone setup a LP plan that looks at an employee's last year of hours worked to determine if he/she qualifies to accrue. I.E.  An employee qualifies to enroll into the plan based off of employee status.  An allotment amount is given if the employee worked a minimum of 1600 hours the past year.  The annual allotment is given on an employees adjusted hire date. Any guidance/suggestions are greatly appreciated! Thanks, Cindy