Short answer: unpbo the campaign and take a look at the mission.
Long answer: I have no idea at all about how to do so. Perhaps it has to do wih the knowsabout command:
player KnowsAbout soldier1 >= 4
For example, put that in a trigger. Where player put the player's name, and in solider1 put the name of the enemy solider. That will check if you know -I don't know whether it works with a human player- everything about your enemy.
Hope this helps