Intro conversation setup

Ok, the past few days I have searched many forums like a maniac trying to figure this one out, with no luck. Somebody has got to know how it's done.

I'm done with the first map of my campaign, everything looks and sounds good; except for the intro sequence (the finishing touch).
I'm not looking for anything fancy, just a simple fade in with some music and a 4 line conversation.
I already know which scripts/talker I would like to use, but how do I implement these sounds into the game?
I know that Valve uses a separate txt file for setting this one up, with some sort of game_event proxy that triggers said event in this txt file. I don't want to use amb_generic or info_remarkable for this.
So can somebody be a dear and sort this out once and for all? It would help a lot of mappers.

Cheers