my @parts = split /([\\@])/, $input;
my $txt = shift @parts;
while(@parts > 1)
{
    shift @parts;
    my $t = shift @parts;
    if($t eq '')
    {
        # get the escaped "escape"
        $txt .= shift @parts;
        # get the text that follows it
        $txt .= shift @parts;
        next;
    }
    $t =~ s/^(\w+)//;
    my $cmd = $1;
    $txt .= "::$cmd\::$t";
}

$txt .= shift @parts if @parts;