I’m sure if Mac works the same as a Windows machine but…
every character in a font has a alt/opt keystroke assigned to it.
For instance the british pound sign in ‘futura’ is ALT 0163 (probably OPT 0163 on a mac)
I use this all the time to get spanish characters ETC to appear in AE. In the windows os there is a program called character map, it will give you the map of a font and all of it’s keystrokes. I don’t know if mac has an equivalent program.
looking at zapf dingbats, the checkmarks should be the 3 key and the 4 key. I’m not sure why you can not get them to work in AE.