Depending on what software you have access to you might be able to produce something like what you are looking for but then again maybe not. You could use a particle system in After Effects and overlay it onto the video. To get someone to appear in a scene is quite simple - just use a jump cut. This means you film the empty scene with the camera on a tripod for a few seconds then stop recording. Get the person to stand in the scene and tell them to jump up once after you shout action. If their appearance has been unplanned get them to look around and act startled. You would then add your star effect at the jump cut to disguise it. Hope this helps.
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Better than a poke in the eye with a pointy stick any day...
Sorry on my lack of detail earlier, I was in quite a hurry. Re-reading it, it's just the kind of topic i'd hate to give the writer some help to if it were on a subject I were skilled in, haha.
I will use After Effects for it, yes The jump cut I understand, easy enough, it's just the partical effect. I'll have a go tomorrow, and post my results.
Glad I could help with 50% of the problem, unfortunately I can't help with the particle generator as my main pc had to go back to HP to get a Bad BIOS Checksum fixed (see other postings on this forum) and won't be back for two weeks. I'm stuck using a 'stand in' for the time being with no software on it. But the general idea is you'll have to create a star shape in a image editor and get AE to make many different sizes and variations of it.
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Better than a poke in the eye with a pointy stick any day...
Star Effect 
The jump cut I understand, easy enough, it's just the partical effect. I'll have a go tomorrow, and post my results.
Linear Mode
