Hanzi deck, sorting, and possibly editing decks via script

I got this deck [Most Common 3000 Chinese Hanzi Characters - AnkiWeb], and it has everything I want, except tags. There’s a field for HSK level “for easy filtering,” but I don’t see any way in Anki to filter by anything but tags. (I want it to only show me cards where the “HSK” field is 1.) Is there a way to only study certain cards if there are no tags? Do I need an add-on?
Assuming there is not, I figured I could write a script to add tags based on the contents of the “HSK” field that’s already on the cards. Is that possible? Because I opened the file in Notepad++ and it doesn’t contain any text.
The deck’s creator provided a spreadsheet with all the data; would it be easiest to just create a new deck from that by using a script? Is there a guide to how to do that? Or a script that does that (or part of it) for me?