Should be, if you have played the ArmA campaign there are those screens where you select the main and auxiliary missions and there is a small screen where a cutsecene is being played.
Since there's no real documentation on how they've done that the only thing I can suggest you to do is to un-pbo the official campaign and see how they did it.
What I'm sure of is that it will be pretty complex stuff
The missions with prefix S, like for example
S07IntoTheEnemyTerritory.Sara should be the 'missions' which include those dialogs..
Oh, and do not double post, please.
If you have something to add to your post after a short period of time (we'd prefer that about 3 days should pass), modify your post instead of replying to yourself.