You have to write a script with all the camera movements like a normal intro but the script is fired by a trigger. For example if you want to start your cutscene after NATO has seized a town (but this is just an example) controlled by Russians, you can create an area trigger with the following parameters:
East - Detected by NATO
TIMEOUT: 60 seconds
TYPE: None
CONDITION: (not this) and apInTown
ACTIVATION: [] exec "myCutscene.sqs"
apInTown is a boolean variable you'll have to set to true when the player or his team reaches the last waypoint in town. For example you can place a series of waypoints in the town to make the group move around it and in the last waypoint in the Activation field write apInTown = true
This trigger is thus fired when the east is not detected by NATO for 60 seconds or more in the town area (so that they think the town is under their control) and the player has reache his last waypoint. When these conditions are met, the trigger will fire the script and the cutscene starts. During a cutscene the player can't control his unit so you don't have to worry about that. Remember to set the acceleration Time to 1 during inGame cutscenes (setAccTime 1) as first line of the script since the player might have increased it before the trigger was fired.
What I don't know is if you have any experience in making cutscenes, that is, if you know how to create a camera and move it around, as well as to use "camera.sqs" to easily get shots for the camera. Can you do that or you have no experience at all?