burning a .dmg file in windows

[jmello]

i've downloaded the three install files for mac os 10.3, but they're in .dmg fomat, which (as far as i know) is a mac-only format.
the mac that i'm installing the os onto doesn't even have a hd in it yet, so networking the two and converting the file to .iso, then sending it back to the windows machine won't work (what google told me to do..)
is there any way to write a .dmg file in windows for a mac?

if not, i've downloaded mac os 9.1, but it's .toast (yet another mac-only format), and i could install that and do the network thing, if i can write a .toast file to a cd..

thanks in advance :D