Section 81 (4) of the Act says this (my emphasis in bold): If the owners corporation is subsequently faced with other expenses it cannot at once meet … it must levy … a contribution to the administrative fund or capital works fund, determined at a general meeting of the owners corporation, in order to meet the expenses.
Just my opinion but I think you are locked into paying for the original purpose for which the money was raised. That said, I think Sir Humphrey is right that no one is going to be jailed if a general meeting diverts the funds to an unexpected and more pressing issue