OK all I'm just Brainstorming here.........a few ideas to help get things started..... no defined process!!!
You WILL have to come up with a new 'year number' ie. 8002 = 2002. Whatever you choose will be incremented forward into all following years so, choose something Finance can live with for the rest of Baan time. You would also need to set up the 'new' year number in Maintain Peiods session for period type and year.
EX: Period type = Fiscal
Year = 8002 (2002b)
then define the fiscal/reporting years' start/end dates. You can re-synch the 'new' year number in the description field for the year ie, 'Year 2002b'. Then, define start and end dates for the periods. These will be real time dates (don't use the 'new' year in the start date).
You would have to make appropriate GL entries to carry the ending balances for September thru the last 3 periods of the current year. You would put the 'new' year number in the 'Next Fiscal Year' field when you run the close year session. (I'm not sure if Baan will stop a close if 'sysdate' is before fiscal year end date! you tell me!
If you use the period description field in maintain periods to re-synch the period/year (Jan 2002b) then, you won't be to bad off as far as report headers. If the start-end dates have not changed, you would carry the GL ending balance from the prev. year close thru to period 10 of your 'new' current year using the appropriate GL entries. and on you go.... You also have to consider keeping the early periods in the new year CLOSED so baan will not automatically create transactions into them. I realize you said this was driven by a production concern but, with ERP your GL is the bottom line to close a year. I'm not sure what else you need to take care of as far as other modules are concerned. There are a lot of common sense efforts you need to do before the close year process that I haven't mentioned because I figure you know them already. This is just ideas to get your periods defined and closed so Opening Balances will roll forward.
I hope some of this will help get you started.