Dear,
I suggest you to have pop up screen at the time of saving material master using transaction MM01.And substitute the profit cneter value with respect to plant.
To get this, use custom table , maintain company code,controlling area, plant code, profit center fields.Update table with respective plant values.Here i suggest you to keep validation at the time of updation of this table.Because BUKRS,WERKS,PRCTR,KOKRS.are linked to each other.So for this valiudation use tables CEPC and T001 and T001K.
This is for successful updation of ZTABLE with plant and profitcneter.Once it is done , then at the time of saving the materila master using transaction MM01 system should automatically substitute it.Here kindly take help of ABAPER.
Fo rthis keep Profitcenter filed in display mode for MM01 so that user will not enter only system at the time of saving material master it will be updated with respect to entries in ZTBALE.
We are using subscreen fucntionality before entering the data in basic data-1.So same way you also can do it.
Hope this may help you little.
Regards,
Pardhu