Since I don't remember the percentil dice syntax....
'dice d%' is not a valid dice string!
That wasn't it.
'dice d100' is not a valid dice string!
'help' is not a valid dice string!
'd100' is not a valid dice string!
Oh, yeah. Number of dice, bonehead....
Rolled 1d100 : 83, total 83
So, (roll)dice 1d100(/roll) is the syntax in question.