IPlot *.pen vs "Old-fashioned" *.plt & *.tbl

I am working as a sub-consultant on a project with a larger firm.
They use IPlot to generate their plot sets. We do not have IPlot, and it is not going to be provided for us. I've never worked with IPlot.
I am trying to set something up so that our plots look as similar to theirs as possible.

Nobody there seems to know anything more about their plot specifications. I asked for their PLT files, and was told there are none. They gave us a *.pen file, which I was told is their "pen table". It doesn't read like a pen table - lots of "IF...END IF" statements. Some of it looks vaguely familiar, but I don't recognize a lot of it. It would appear to be some sort of IPlot "Design Script" file. I've asked their CAD guy for clarification but this was already in place when he got there. "It works, so I don't ask a lot of questions."

I need to set up a plot driver and pen table to simulate their plot set-up. How do I break this IPlot thing down into something I can actually use? Does it contain the same information as a plot driver and pen table? Where?

Thank you for your assistance.
MaryB