How to change existing assets WDV formula to change from PTD to YTD

Hi,

we are on 12.0.4 version

we have almost 450 assets

Please find the attachment for WDV Method (Screenshot)

I have also attached screenshots of existing asset and depreciation sheet exported from system

Currently client is working on excel sheet following example is picked from client sheet

Client Requirment:

     F                       G                 H               I                   

Date in service     Rate %          Cost     Opening amount                                                           

                                                                  (NBV)

31-Dec-2011          10%          24,000          4,133.98

 

           K                                      M                            N

Depreciation Amount              Acc.Depreciation          WDV

(YTD Depreciation)

1,324.40                                5,458.38             18,541.62

=(H302-I302)*G302/100/12*$I$1               =I302+K302                       =H302-M302

      

How can i do this calculation in system ? PLEASE REMEMBER i have to replace this calculation to the existing asset in system (almost 450 assets) example is shown in screenshot