Well you'll have to do 2 major things before you go to apply your effect.
1) Track the phone inside your footage, using the built in tracking tools (same as in CS3 exept for Mocha AE)
2) The you'll have to rotoscope the hand/fingers to create a matte for the layer where you are going to apply your shine/highlight effect.
There is no easy way to do this, and it's a very tedious job. If you go to AE community help and search for Rotoscopy and Tracking, you might find really interessting tutorials on how to do these step.
Hope that helps,
As Sébastien said, this will have to be done mostly manually at this point. If you had an option to control the filming, you'd simply use a colored phone and derive a matte from it, but that opportunity is now gone, it seems. Familiarize yourself with the masking tools in AE. Also keep in mind, that Shine, Starglow and most other glow/ glitter/ glare/ rays plug-ins have built-in threshold controls, so if you're lucky, you may not need to mask everything but can rely on that to give you the correct highlights based e.g. on luminance.
Thank you both.