[h-e-w] ps-print duplex printing?

[Brown, Stephen D]

I'm using NT Emacs 20.7.1 on Win2K, and I'm trying to use the duplex
printing option for my printer.

At first I tried to just set up the printer driver to default to printing
both sides, but that did not work when I printed from emacs.
I then found the PCL Printer Command escape sequence for duplex printing on
my printer, but I don't know how to pass those parameters using Emacs.  

Can someone tell how to pass these esacpe sequences using Emacs, or am I
going about this the wrong way?