I'm kind of in the same boat. I need to write a lisp to create a page setup for a plotter.
I am currently just importing a page setup from a template I have created for myself. Unfortunately, by importing a page setup, I have to have several page setups, one for each scale of drawing. It gets a bit cumbersome, but would this be an option?
If importing is not a good option, can you give us a little more info, perhaps a pseudo code for starters?