Damn, i played this a few months (maybe even 1 or 2 years) ago.
@ smiluu- Get the timed explosives, they are on the clock and somewhere else. Blow with them the door. The inside of the room shouldnt be much damaged, but unfortunately there isnt too much of a suprise in it.
Now, the room with the dog, a soldier and a sergeant might give you a few laughs.