Automate creation of link between Account and Natural Account Number

Hi, As part of implementing China Localization, I have a requirement to automate the setup of Natural Account Number mapping within P0901.  The number of accounts in the chart and number of business units means we would have to do the manual linking over 40,000 times.  This is not feasible manually.  Can anybody give any tips or advice?

I am currently looking into the possibility of modding P09801 Copy Account to Business Unit but would like advice if there is a better (and hopefully standard) solution.  A solution within JDE is preferable over SQL update so that the Finance users can do it themselves when new business units or accounts are created.  The current thinking is to set up the link between Object/Subsidiary and Natural Account Number within a model chart for the China company and use that as a lookup when creating new Business Units.  I expect it won't be that simple, but that's the starting point