Plotter Driver Inheritance?

I have a plotter driver that we use at work that creates a CGM.

It had the following line set:

default_extension = 'cgm' ; default extension for cgm

When it was ran, the printer driver would open a "SAVE AS" dialog box and you have to navigate to the correct location and name the file correctly. Well, I was just doing some R&D and discovered that you can comment OUT the line above... and put in this line:

default_outFile/auto_overwrite = \\path\you\want\to\auto-set\FileName.cgm

And when you run the plotter driver NOW? I auto creates a file called FileName.cgm at the "path\you\want\to\auto-set"

My question here is this...

I'm a programmer, so forgive me if this seems unreadable. I'm thinking programming concepts here like Abstract Classes and Inheritance. My thought is this. I want to leave the Plotter Driver mentioned above completely alone. I want to create a new Plotter Driver just for (let's say) Stormwater pages. The new plotter driver should inherit ALL of the functionality of the one mentioned above (without my changes) BUT it should auto-set the FileName and Path for the CGM it creates?

In our department we put Stormwater CGM's in one folder, Wastewater in another, etc. Ad Nauseum. I'm trying to come up with an idea to build on this concept. By creating a Stormwater Plotter Driver that inherits, if management ever makes a change to any of the core concepts within the Main Plotter Driver, then all of the ones inheriting from it would auto-adjust to the new settings instantly. AND it would allow us to have quick and easy Plotter Drivers for common prints we create.

Anyone got an idea?