Go to any shop find ur desired number with any operator and use number portability to choose ur desired network.e.g,u get ur desired number from paktel which is like 0304-1234777,But u wanna use mobilink as ur operator coz most of ur contacts use mobilink so u just go to the mobilink office and tell them that u wanna port-in ur number to moibilink.they'll charge a monial fee and that's it.