Open Sales order details in APO

Hello Guru

I have a requirement where I want the report of open sales order till current date in the APO system. I have already explored below tables:

/SAPAPO/POSMAPN – R/3 Object = 3 (sales order), Sales order Number

/SAPAPO/ORDADM_I – Time stamp created on, Product ID, location ID

But am not sure how I can get which are the open sales orders from that. Or is there any BAPI or FM which I can call from APO to ECC to get this details.

Regards