Support for Sony STR-DG520

[Govidad]

Hi, I bought this set about two years ago in Netherlands but I cant play songs/videos directly from my PC. It has a DM Port at the back and the manual says I could connect my PC to it. The cable is however not supplied. How do I then connect this amplifier to my PC (3.5mm) audio socket? .It does not have an aux input but an earphone socket. I particularly want to use it to play songs from my computer. Please help