If you're talking about possibility, then yes. Flash is a Turing complete language, and can theoretically describe any idea or thought with mathematics and basic logic.
My code that you quoted above relies on the assumption that the deck is a series of objects stored in an array-in plain english, all the cards in your deck are listed with their attributes in a random order. I derived this assumption from the fact that cards like eternity and reverse time can alter the cards at the top of it. I am not 100% certain that Zanzarino implemented decks in that way, as the reverse time effect can easily be replicated with a small alteration to the card-drawing script to first check if there are any reverse-timed creatures in a separate list. While it is an ugly and inefficient solution with potential to introduce bugs, it does still work. If my assumption does happen to ring true, not only deck searching, but sending card to the bottom of the deck, shuffling the deck and targeting cards within the deck will be possible.
Will it be beneficial to the game? Maybe. Depends on how it is used.
