Excise No. using Accounting Document Number and the P.O. number

Hi All ! In my GL report, I'm displaying the Accounting Document Number and the P.O. number.

Now, the requirement is to display the excise no..

Tried different tables in SE11 using J_1EXC for excise detials, but to no avail.

And last which vendor to pick, Because vendors in P.O and BSEG differs.

If I use the BSEG-BELNR I get a different vendor & If I use the P.O. no. in EKKO then also I get a different vendor.

Please suggest.