To further Annatar's response: what you described has been tried many times by many people, all with effectively no success.
The closest thing anyone has accomplished has been to create moons within a planet's gravity well. Depending on the modder's capability, these have even been made to orbit the planet, or at least move in some fashion. While cool, these moons are not colonizable and only there for visual effect.
So yeah: sorry, man. You're not the first to come up with it, and definately not the first to think it'd be really cool, but efforts have largely died out due to the futility of it.