Once you get in and show a good GPA they may offer you a merit scholarship but it is very rare since people are usually getting 4.0s very easily. Also as far as need based scholarships are concerned u have to apply for them when u apply to the university, that means financial aid applicants need to send their forms with the same application form that u send when u apply as a regular admission. Well they dont have a separate form for Financial Aid. They just have an additional side to the form. Also it doesnt decrease ur chances to get in, I just said that when u apply for Financial Aid they have a separate pile for all those students and then they compete with themselves since all universities have a certain number for scholarship applicants and the rest are those who pay.
Please note, there is a scholarship dedicated to people who are living in remote areas which is called N.O.P. Try finding out about it since it pretty much has alot of seats and the criteria is largely based on whether ur financially not that stable. And above all else if u can afford LUMS then dont ask for aid, many cheaters often potray themselves as beggars(yes I know people in their freshman batch who have done this) and try to scam the uni into thinking they deserve it. You might as well be taking someones else's future down the drain.