Connecting laptop to receiver for sound

I’ve connected my laptop to my TV with an HDMI to DVI cable so that I can watch movies.

Now I need to connect the sound.

I have a 5.1 surround connected to a receiver. So I just need a way of connecting my laptop to the receiver via RCA.
My laptop has a standard mic port and headphone port. What kind of cable do I need to get? Note that I want to be able to get dolby or DTS sound as the movies are all in dolby or DTS.

Thanks in advance.

Hi and Welcome!

I would try the headphone jack.
If your laptop supports dolby/DTS whatever should be mentioned in its manual, also the needed adjustments of the audio driver (with some audio devices, the input/output jacks jan be reconfigured) and required cables should be explained there.