Assuming that you are using A2K or above, (I don't know haw far back MVSETUP goes back in AutoCAD), you can use the command MVSETUP. It will walk you through the steps of assigning scale to paper size. Once I do this, I put the outer rectangle on the def. points layer. I then proceed to fill out the rest of the border. You will have to print out the border, to see if the outer limits of the border prints out on your printer. Then you will need to adjust your border line until they print out on your printer.
If you need further assistance, just ask.
