How come there are no listings for sky_night_01? The upload history for that image suggests that's the skybox for plr_pipeline, but there's no light_env info for that map.
Ah, you're right the light_env properties aren't listed for that one...I believe I scoured a decompiled Pipeline for its information actually - I'll go through it and list the numbers to put in tonight. If you can't wait though, decompile or look for the .vmf of Pipeline online somewhere, open it in Hammer, go to the Entity Report option in the Map tab at the top (I think its Map...definitely one in that menu list) and look for the light_env entity. Click/Highlight it, then hit "Go To" and it'll shoot your 3D Perspective view right at it. You can double click it as you would on any other .vmf, and jackpot: there's your light_env info to copy+pasta.
As I said, I'll update the list tonight myself anyways - thanks for pointing that out!