You probably can. DosLib (Autolisp add-on functions) has a few print handling functions. You will have to configure a separate system printer driver for each layout/size combination, and name them accordingly. Then, create a small lisp routine for each configured driver. Here is an example (requires a printer "A3L" to be configured):
;A3 Landscape
;Start print with A3L
(defun c:A3L ( / )
(if (not dos_regset) (xload "doslib4.dll"));Loads doslib if not loaded
(dos_setprn "A3L");Sets "A3L" as current system printer
(command ".print");Start print command
)
;End A3 Landscape
These routines can be created directly in your Icad.lsp file. The file doslib4.dll must be in the Intellicad search path. It can be found here:
ftp://ftp.mcneel.com/pub/doslib/doslib4.exe