Realtime lightning (rtlights) are added via the ingame rtlight editor (g_rtlight*).
There's a more easy way: add an rtlight ingame, and save the rtlight file. Now, the rtlight file is pretty easily understandable, so you shouldn't have problems copy pasting lights in it. There's only one thing you need to know: the coordinates for the lights. You can get coordinates from netradiant. Eg. create info_null entities where you wanna have rtlights. Select them, filter out the rest of the map, and save the info_null files into another map. Now, simply open that map file in a txt editor, and you'll get the coordinates for your rtlights
