I also was looking for such program, to be able to extract a vcd file. I googled a lot and found something called CDemu too. It wasn't on the portage, so I didn't bother testing it, but if you have the courage, you could give it a shot. It's supposed to work in the same fashion as daemontools on windows.
I then proceeded to continue my noble mission =). Which lead me to finding a program called vcdgrab. It also isn't on portage, but the installation procedure didn't look too complicated, so I gave it a try and succesfully installed it.
The programs is pretty much in beta stage, but it worked very well. Project homepage can be found at:
http://vcdgrab.sourceforge.net/
In order to install you have to extract the contents of the package:
tar -zxf vcdgrab-0.1.tar.gz
then do:
./configure
then:
./make
After that you (mostlikely, at least hopefully) got the executable and can do:
./vcdgrab /path/to/the/binfile/blah.cue
and as a result you got the avseq-file. Hopefully this is of any help.