How to carry over values differently (aggregated or not), or is it possible

Dear all:

In our Account Dimension, we have Beginning Inventory Qty, Ending Inventory Qty, Purchased Amt, Sold Amt, etc.

When we run reports with calculated time members, such as 2008.Total, 2008.H2, 2008.Q4, etc, most of our Account displays correctly with proper aggregation (like Purchased Qty, Sold Qty is summation of all child months'). But in particular for Beginning Inventory Qty and Beginning Inventory Amount is where I am having trouble.

For instance, for Ending Inventory Qty, we assigned ACCTYPE AST, so the report ignores aggregation and carries the last month's value to the calculated time member. However, for Beginning Inventory Qty and Amount, I wish to assign the values of the first month. If it is 2008.H2, then 2008.H2 Beginning Inventory Qty should be the same as in 2008.07. Another example would be 2008.Q4's Beginning Inventory Amount being the same as 2008.10's.

Is this doable in BPC?

Thank you!

Brian