use Modern::Perl;

my @replace = map int(rand(99999)), (0 .. 10);
while (<DATA>) {
    do {print; next} unless /^eval/;
    s/(?<=\[)(\d+)(?=])/$replace[$1]/ge;
    print;
}

__DATA__
@a = ("'hello world'",'print ', ';');
eval("$a[1]$a[0]$a[2]");