The light bulb just went on....
I now see the mis-communication problem we were having - my fault. I can not think of a good solution for you - at least not without modifying Baan source and such, and then I do not even know if it would work. I do have a couple of ideas - certainly not what I consider good ideas.
The first is that you do not change the devices or anything, but instead create a baan session that runs in batch mode (or continuosly) and searchs the device queue table (ttaad320) looking for your report. It could use the print date and time stamps to check against the last run time of the job. Then when you found one you could kick off another session to manipulate the report. This would require that the tmp files not expire, so the delete delay would have to be long enough to let the job run.
The other idea requires that you change the device type on all the printers concerned. Just so you can run your own ttstpconv. This could launch your 4gl script and then send the report to the printer. But from your message this sounds like something that you do not want to do.
Just some random ideas. Hopefully someone has better suggestions or a solution!!
Good Luck! Oh - if you do find a good solution please post it here for all of us.