SAP HCM - Payroll Posting - Finding personnel number for a credit Memo

Question

Hi,
We are currently trying to trace the personnel number associated with a vendor posting from HR-FI. A credit memo has gotten generated against the vendor (union dues vendo).
The FBL1n transaction yields only a consolidated result.
The document number on FB03 displays the line item but without pernr
The PPOIX, PPDIX, PPDHD, PPDIT, REGUH, PAYR and the T51R... series have not yielded the pernr for the specific line item.
The information we currently have:
Run Id:
Document Date:
The amount on the credit memo:
The posting document number:
The transfer line number from HR to FI
Line number on the posting document:
The payroll area of the employee
The wage types associated with the vendor
Need your help on the following:
1) Is there a different place that credit memo needs to be looked into? Have we missed out any table?
2) How do I use the posting document line number, the transfer line number, the document number and run ID in PPDIX to track down the pernr?
Thanks,
Amit

Answer 1

Hi Ted,
Thanks for your response.
One thing I missed out in my original post is that this is third party posting entry.
I have the LINNUM and RUNID. But when I input those values in PPOIX, the search is not returning any results.
This is a third party posting so my EVTYP=TP. Is PPOIX geared to return only PP values? Is there a way I can find the PP correspoding to these line items.
I encountered a couple of problems when I ran through the flow.
From credit memo (FI posting document BKPF), field 'AWKEY' is the reference document back to posting document on payroll site.
I got the AWKEY
Use BKPF-AWKEY and GL account  on FI line item you're interested in (BSEG-ALTKT) to get field 'DOCLIN' in table PPDIT (PPDIT-DOCNUM = BKPF-AWKEY, PPDIT-HKONT = BSEG-ALTKT) .
When I looked at BSEG table, I noticed that ALTKT and HKONT are different.
The HKONT has the same GL account as the GL account in BKPF. Itu2019s a/c payable outstanding checks.
But ALTKT value has an account I couldnu2019t get in chart of accounts. Probably a clearing account? Also the original Accounting document line item has a vendor a/c which I believe is in turn linked with G/L account.
So when I input DOCNUM, HKONT in PPDIT, my search is not returning any results. For that matter even with BSEG-HKONT that I described above, it is not returning any results. 
Use PPDIT-DOCNUM, PPDIT-DOCLIN to get 'RUNID' , 'LINNUM' from PPDIX (PPDIX-EVTYP = 'PP', PPDIX-DOCNUM = PPDIT-DOCNUM, PPDIX-DOCLIN = PPDIT-DOCLIN).
Since evtyp under consideration is TP, this is not returning results. If I take off the PP input, it does return Line Number and Run Id.
Use PPDIX-RUNID, PPDIX-LINNUM to go get PERNR from PPOIX (PPOIX-RUNID = PPDIX-RUNID, PPOIX-POSTNUM = PPDIX-LINNUM).
Does not return any results.
Sincerely appreciate your help.
Thanks,
Amit