[webber]

if the .cdi is a dj2 image then you can use cdirip found at dccopyworld.com in the utilities section , i don't think it supports converting dj3 images yet, but i might be wrong becaus i have not used it in a couple of weeks so there might be an update.

yes you can you need to use cdirip to rip the .cdi into two tracks one audio which is either .wav or .raw and .iso, you burn the cd in a multisession fashion manually first burning the audio track with winoncd and then using (i use winoncd again) burn the .iso and close the cd.
the key is to make sure the LBA from the first burnt session matches that LBA which cdirip reports for teh second session when you are ripping it.
You need to reduce sectors for the first session etc...
all the info you need can be found here http://dcxeal.virtualave.net/faqs.html

regards
webber