That is only possible if the DVI port allows audio when used with a DVI-HDMI adapter or cable, and then it won't work with a normal adapter cable either. It has to be done with an adapter like this noe, Newegg.com - HIS DVI to HDMI Adapter for HD4K Series Model HHDMI4071
that came with some ATI cards (and Nvidia as well) from the HD 2xxx series and up that didn't have a HDMI port on the card. That adapter is pinned/wired differently than a regular one to allow the audio to pass through the DVI port, which is also pinned a little differently than a normal DVI port (basically makes use of the unused pins in the DVI connection). There are the odd places that carry a DVI-HDMI cable that will do it, but they aren't easy to find.
If the DVI port on your laptop doesn't support that sort of thing then the only way to do it is the old fashioned way, with the DVI-HDMI adapter/cable and a cable from the speaker jack on the laptop to the TV.
Just saw your edit. Your friend have an adapter like the one I linked to above?