Need FM/BAPI to create Purchase info record

Hi All,

I need to create Purchase info record using BAPI / FM , but i am not able to get any relevant interface for creating PIR.

I do not want to use BDC , please let me know if any BAPI/FM exist for achieving the same.

Also i need to create PO against PR and Sales order . I got the BAPI - BAPI_PO_CREATE1 but i could not find the place where i can pass the sales order so that PO can be created against Sales order.

Please help me to get the required interfaces.

Thanks,

Abhishek