You would probably need setFromDvar, which is removed. And you can't pass an argument in the form of a dvar to the "say" command.
For example, if I did:
set v "^1This is a message"
say "vstr v"
It will just say vstr v.
I guess this could work via GSC, but would be kinda pointless as you could only make a 4 character clantag :p