my @a = (1,2,3,4,5);
for (@a[1,3,4]) {$_+=10};
print join( ',', @a), "\n";

# or

my @a = (1,2,3,4,5);
sub foo { for(@_) {$_+=10} }
foo( @a[1,3,4]);
print join( ',', @a), "\n";