Yup! :'D You can do that for all plz accounts, so would be :iconspazzattackplz : without a space. You can find the name of the account by hovering over it with your cursor, and the name will appear. Then you type that in :icon _accountnamehere_: don't forget the plz!
This is also used for accounts, so you just do :icon_their-username-here: So, would be yours. If you do that for someone, they will get a notice in their inbox telling them they were mentioned, unless they disable that notification. You can also do ~mingplz or ~impopulargirl9 which will also tell them they were mentioned.
Plz accounts are basically accounts used just for their avatar and are usually not owned by anybody. Have fun! c: If you need anything don't just ask