Is there a way to enable Rating Button Feature on EOS 5D2?

[Alipacman]

Hey guys,

I'm a computer scientist and absolutely new to this whole area, since I do not even own a camera. I'm just here for my girlfriend because she told me how much she would love to buy a new EOS camera just because her EOS 5D2 misses this 'Rating Button' feature. Therefore, I thought there might be a hack for it, since it is only a software limitation.
Is there a way to activate this 'Rating Button' feature on her camera?

Thank you for your help