Procurement type change in future for MRP

[chiken]

Hello everybody,
i have a question regarding engineering change with validity in the future and MRP.
Our planning office knows that from 01.12.2010 some materials will change procurement type from F-30 to E.
We have tried to use tranasction MM12 and MM13 but this does not function for us becasue the change is activated only at the date (i.e 01.12.2010), and before that date MRP takes into account procurement type F-30 also for requirements in 2011.
There si a way to make MRP create subcontracting order till 30.11.2010 and planned production order after that date?
We are trying to use engineering change number, but up to now we haven't found a way to plan changes of material master and have the changes then taken in account in the MRP according to schedule changes dates.

thanks in advance for help, this is a serious problem for us.

Kind Regards

Stefano

[Ramarao]

What is your planning horizon, and what are you going to do with the planned orders that are after 30-11-2010 if system generates them as planned orders?