Let's not give up yet
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I don't know if Debian Squeeze can be installed on your NAS; if it is so, in theory you should be able to install, share and use the printer via CUPS or Samba. If you're not familiar with Linux, it's not going to be easy, though.
Try installing Fonz Fun Plug on your NAS. The guideline can be found
here. There's no need to follow the instruction below "Change root password", since FFP is just a mean to achieve your main goal (installing Debian, that is).
If it worked and you can connect to your NAS via telnet, run the command
uname -a and paste the results here. The Debian version you'll be using depends on the Linux kernel version (2.6 = Squeeze, 3.x = Wheezy).
CUPS info:
here.
Linux drivers for CLP320:
here.
Good luck
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