$1-
From Scriptwiki
You can use the $1, $2 ... $N to refer to N'th parameter in string. You can also use $N- to refer parameters from N forward and $N-$M to refer to parameters from N to M.
Examples
In aliases $1- starts from the first word after the call of alias.
alias shout msg $active HALLO: i just said $1-
Usage: /shout i like milk.
Usage in events is simple the same.
on *:text:#mirc:!repeat *:{ msg $chan $2- }
$1 would refer to word !repeat.