Help : recording with TOSlink cable
 

so,i have a soundcard with digital in & out and i want to record on my hd the things i have on some MiniDiscs using the digital TOSlink cable,but the recording program i use apparently do not support the digital in , there are the usual aux/stereo mix/mic et options but no digital in,and choosing one of those result in no sound recorded.do you think this is a problem of the recording software (i have only Audacity on the pc with that Sound Card (a cheap Terratec aureon 5.1 pci )
or could the pc have some problems detecting that audio input(drivers seems to work properly,with a standard 3.5 jack i can easily record from the line in or mic plug and sound works with itunes,games etc)?
hope someone can help me...

help help....i need help....