Co11n operation confirmation - costing calculation

hi

I explain you my requirement. For example, If there are four operations.0010,0020,0030 and 0040.

0040 Operation is Milestone Operation.

In co11n Screen, when i enter production order and select 0040 Operation with confirmation acticity2 - 4 Hrs , activity3 - 1 Hrs , activity - 2 Hrs

And i am making the Activity1, Activity2, Activity3, Activity4, Activity5, Activity6 for operation 0010,0020,0030 as zero instead system default values.

This is acheived by enhancing befor updating AFRU in include LCORBFAZ and enhancing AFVV in include LCOVBF10.

So , the previous non-milestone operations are posted with zero activity , and its reflecting in AFRU,AFVV

but still the costing is calculated for the operations , for which the activity is made zero too.

Suggest me some solution to overcome this , immediate help required.

Thanks

Arun