$var2 = s/123/456/g (tr/a-z/A-Z/ ($var));

##</code><code>##

    sub apply (&$) {
        local $_ = $_[1];
        $_[0]->();
        $_;
    }
    
    $var2 = apply {s/123/456/g; tr/a-z/A-Z/} $var;