Hello Volker,
I think, the easiest way would be to read table RSPCABAPASYNC. I expect, you know the variant name of your ABAP-Process. The field LOG_ID shows your current process-chain. These chain can be read using the table RSPCPROCESSLOG.
If not, you will have to go further: Look into tabel RSPCVARIANT and find your report ( Field "PROGRAM" = sy-repid ).
Then, go back into RSPCABAPSYNC and look for the current running process, which have your variant.
Kind regards,
Hendrik