Virtualising a VERY legacy app

Looking for a bit of help on this one. I have a customer who has a VERY old MS DOS application that is written in some 3GL language of unknown origin. The original software vendor went out of business back in 1996 or so and no support.

I need to virtualise this application as they neither want nor have the money for a more modern solution.

Virtualising the machine is easy enough. However this app spits out HP PCL codes for printing and will only work with HP Laserjets.

To make the system work I need to be able to print to non PCL printers (ie a Samsung laser printer) and potentially, print to PDF.

Any ideas on how to do this are greatly appreciated as this is really a job stopper. Is there some sort of shim available or am I barking up the wrong tree?

I would suggest using printers that support HP's PCL codes or HP PCL emulation. It's easier to change a printer/device than rewrite a legacy application.

I work with warehousing/production unattended printing from a legacy application. I have to validate the printing solutions, so it makes sense to have a limited number of devices you need to support.

For the PDF issue, in the past, I've needed to use a commercial PCL-to-PDF add-on. With Linux, we've been able to handle this with open-source software.