Two ways: you either use the camera.sqs or as mike sugested a game logic (which is I must say a lot more convenient after playing around with that for a while ;D)
first way: put
this exec "camera.sqs"
into the initialisation field of your player on the map. If you switch into preview you are in camera mode and can move your camera to the positin you want (try with A , Q , S , D keys to move around if i recall right)
Once you found your camera position press ctrl ONCE. Now have a look in the main directory of OFP for a .txt file (forgott the name but it would haven been created rather recently
) in there you will find the coordiantes of your camera...
second possibility is a lot easier: try game logics as mike13021 sugested int this thread...
hope that helpes..