Columbia does not publish WL #s but other top schools WL between 10 and 30% of applicants. That’s right, applicants. Even if a handful get off you’ve virtually no chance.
So follow their instructions. Some have a form. Some want a letter. That’s it.
Then move on. In reality WL is a rejection. Not saying to be mean but people need to fall in love with a school that loves them back !! The WL is there in case Columbia falls short - it’s not there for your benefit.
Best of luck.