"second" personal statement

[strawberry mcflurry]

is it true that you can send a second personal statement to LSE after you've sent the ucas form off? i heard its sort of like a covering letter

im applying for mainly economics courses but one of my choices is for Accounting and Finance at LSE. i was told i could send a "covering letter" once i've sent my ucas form of to explain to LSE why i want to apply for Acc and Fin. most of my personal statement is about economics and not much about acc and fin

please help
thanks