How to make MPP to calculate work automatically to individual resources assigned to a task

[vspb27]

I have a task having work for 90 hrs. I have three resources. One of the resources (Res3) is going on leave for 6 days, starting from tomorrow. Start date (Day1) of the task is today. When I assign three resources to this task, what is happening is the work is divided equally among the three resources (30 hrs each) and the end date is calculated for the task. End date is only after the Res3 come backs to work. I want the MS Project to allocate the work automatically based on the availability of resources. For example the MPP should automatically allocate work for resources as follows:
Day 1: Res1 (8hrs) Res2(8hrs) Res3(8hrs)
Day 2: Res1(8hrs) Res2(8hrs)
Day 3: Res1(8hrs) Res2(8hrs)
Day 4: Res1(8hrs) Res2(8hrs)
Day 5: Res1(8hrs) Res2(8hrs)
Day 6: Res1(1hrs) Res2(1hrs)
And end date should be Day 6. It would be great if you can let me know how to achieve this.

[JAMES_911]

I suppose it could be done with VBA but I can't imagine any real world project where the duration of each task in the project would be double (or any other fixed ratio) of the duration of the task that preceeds it. Work estimates just aren't that tidy.