query to calculate NBV as of current and past periods

Hi

Would anyone be able to tell me if there is a query for calculating NBV as of a date (this can be latest or past period) for all types of assets.

I have a requirement to identify all assets with an NBV <> 0 in Dec last year. The query should accept ASSET_ID and a date(or period name) and calculate the NBV.

I was using a formula to calculate NBV based on difference between End Balance and Depreciation reserve. But this formula is valid for CAPITALIZED assets, not CIP Assets. And secondly it requires at least one record to exist in the fa_deprn_summary table and does not use Orignal Cost at all. i.e. if there are no records in Deprn Summary table, or depreciation started later than Dec last year the formula will not calculate NBV.