Hi Orly,
Could you enlighten me whether will you be posting depreciation in tax area or is it meant only for reporting purpose.
If the answer is for reporting I would say you can play with depreciation key where
system can post depreciation based on yearly basis.
Please explore in this area I have done this earlier but scenario is no matter the acq date system will calculate complete depreciation for the asset..
Kindly get the complete requirement certainly few things cannot be done in sap without enhancement.
regards
Plato Bose