DD-WRT should be able to.
In the web interface, make a new virtual interface called "ath0.1".
Then SSH in and issue this command
root@DD-WRT:~# nvram set ath0.1_ssid="┓┏ 凵 =╱⊿┌┬┐"
Go back to the web interface and hit "apply"
It may give you an error, but it should start working.