try DiscJuggler?
also games will need to be self-bootable to work in NullDC. you can use something like exoboot to do this.
there are various nulldc wrapper scripts out there.... check out
http://gameex.info some have been posted there that you can adapt....
the premise of my own wrapper script is to run daemon tools to mount the image, run nulldc and unmount when its done.. it also runs nomousey.exe -hide before running nulldc to hide the mouse pointer...and runs it again to reenable it... and also does "pskill" (kill process command from sysinternals guys) for the various daemon.exe,nulldc.exe in case things get hung up.
and full screen can be enabled by default in nulldc.. u just need to edit the .ini file .. its pretty simple altho the setting appears in 2 places, only 1 is used depending on your config.