Retrieve data like rework %, schedule and effort varience from Microsoft Project

Question

Hi,

I need to generate various metric from my MS project file for the period of one month. I need to generate following reports

1. Schedule Variance
2. Effort Variance
3. Rework Percentage
4. Wasted Efforts

For rework percentage, I am using condition like the task.Start date should be greater than or equal to the start date and task.Finish date should be less than or equal to finish date.

but I am concerned about the tasks those are starting before the start date and ending before the end date. In such situation I only need the rework % for the number of hrs spent during start and end and not for the hrs spent before start date.

Same thing applies to the task which are starting before end date but ending after end date.

Any pointer would be great help.

Thanks