UNIX for Beginners Questions & Answers

I have been searching for a solution to a printing issue for several months now and have come up with no decently working solution. Please give input.

We have an old inventory control program running on TRU64 Unix V5.1B operating system. Around 2003 it was virtualized onto VMware via AVT's vtAlpha emulator. The program appears to have been written to print it's own internal events to two files (log_file and log_file1) which are then lpr'd to printers (control and logger) set up in the operating system via printcap and then the files are deleted. The printcap file showes these printers to be lp=@ip.address:9100 which are old HP print servers (lan to parrallel) with simple text only dot matrix printers attached.
These two printers print an average of about 3 single line entries per 1 minute, 98%+ of which is not needed. There is 1 print job (about 6 lines of text) submitted and printed every hour with an inventory update, which IS needed. Therefore, I cannot just redirect the printers to /dev/null.

We cannot just turn off the printers because the spooler then stops once it gets to about 100 entries and the program hults (but not the system). I say this because we can go in and purge the print queue (via lpc) and everything starts working again.

I did figure out that if we turn the spooler off, the log_file and log_file1 do not get deleted, but are instead appended to. The problem here is that 1 weeks worth of "held" printing ended up creating 1 log_file a little over 350KB and crashed the entire unix system because it filled up the minimal available disk space. We did have a backup of the VM, but this created about 8 hours of downtime till we cleaned up and updated the program's internal database.

A few things to mention...
1: There is a network obviously, but everything else is windows based.
2. There are no programmers that are willing to try to tackle re-writting the software (internal or external).
3. Everything that is "printed" is actually submitted to some sort of file and then that file is spooled to the printer (the log_file and log_file1 are just some of the files) then the files are deleted.
4. If these files exist, they are appened to and not over-written.

I am not sure what options I have, therefore I do not have specific quesitons on how to do something.
Can we change the printcap to print to a file or something else somewhere else?
Can we set up some sort of filter that only prints the information we want and just ignores the rest?
Are we just stuck and have to keep replacing print cartridges and paper regularly?
Is there anything else you would like to know to help you help me?

Thank you in advance.

google 'sysv printing with cups' and write a script to bypass any output you don't want.