OK. Even easier, assuming that has board optical. You don't need Dolby Digital Live or DTS Connect. They are mainly used when gaming because games do not have Dolby Digital or DTS audio tracks. Media that has Dolby Digital/AC3 or DTS tracks, such as DVD/BDs or some movie/video files, the stream is passed on for the receiver to decode.
If whatever media is only stereo, that doesn't matter as the receiver in the Sony system should apply Dolby Pro Logic and up mix that to 5.1.
If the motherboard doesn't have optical, then you'll need a sound card. You don't need anything fancy, so long as it has optical. Asus Xonar DG or DGX would be a good choice.