Hi Rish
You can try to think about realignment functionality if you just want to transfer the FCST from one site to another site. (assuming site is part of CVC combination).
Please find below the document for your reference.
APO Data Realignment & its importance
You can also use the excel upload functionality in APO BW and load respective forecast from cubes to planning area. Please find below the document which could explain you the stets.
Please let us know this information helps you.
Thanks
Amol