Fixed Assets account generator and workflow question

Good Day friends,

I have a specific question; we are in about to go for our CRP 1 for Fixed Assets R 12.1.3 and we have Oracle Grants as well,

 we are  importing  the  Project information from Req`n>Po to Fixed Assets now we are inserting the asset clearing account in the requsition workflow stage along with the project infrmation  but the problem comes post mass aditions and during the create accounting process  we have to replace the Asset clearing account with the  asset cost account so that we can transfer the asset balances into GL ,I need guidance as to how and where in workflow FA or PO workflow do we make this switch .. i saw asset clearing ccids and also saw the asset cost ccid`s in some table... need some guidance please