Ok, if it DID work, how would one redirect the USB/Printer port to mimick a printer port (LPT1/2/3..)?
If it did work on a physical machine, you wouldn't need to do anything, as the software for the USB parallel adapter would normally present LPT2 (or whatever) to WIndows.
...The Xeltek Eprom Programmer is only a few years old (late 90s)and the operating software goes up to XP, but it REALLY wants to find it at a printer port. It seems to me that there should be some way to communicate with the USB/Printer cable, but I simply have no clue with USA protocols at this time.
The issue is that these USB adapters generally only work with
printers. Sometimes scanners and cameras, whose software fiddle with the handshaking lines. But nothing that tries to access the parallel port UART chip directly.
Do a search for parallel port dongles on these forums (such as
this one ) and you'll see that you're in a similar situation. And these dongles are often for multi-thousand dollar software so it's no small matter either. The dongle users are sometimes lucky to be able to get a USB version of the dongle. That may be your only realistic solution (i.e.: replacing the programmer), other than finding an old PC.
Realize that the "few years old programmer from the late nineties" is actually a decade old. (We're now near the end of the first
decade of the 21st century!) While the software may have worked in Windows XP, it's likely that it was a 16-bit program designed for Windows 3.1, that the company was just lucky to have still work through Win9x, 2k & XP. And using parallel ports for non-printing is really technology from the 80s. So the design of the programmer is more like 20 years old, not "just a few years."

I know that doesn't help you're situation, but just trying to get some perspective.