Toslink to RCA adapters

Does anyone know if you can use a digital audio interconnect cable in a Toslink optical circuit by using adapters? Do such adapters exist and would this work? The digital audio output on my blu-ray player isn't working but the optical output is. I have a 6 meter digital audio cable in place and don't want to invest in a 6 meter optical Toslink cable. This is for a blu-ray player to connect to my Rotel AVR. Please advise. Thanks.