I think making a pseud would probably do what you want. I don't have any myself, but I read a few writers who use pseuds, and it looks like the fics posted under each pseud show up on the pseud's Works page but not on their other pseuds. So it would probably be ideal for what you're looking to do. (With the caveat that I haven't done it myself, so I'm not entirely sure what it looks like on the user end.)

(also, hi! :D)