It may well be that my solution misses the goal. As far as I understood it, nothingmuch wants two slots in an array to contain the same scalar, and I believe that my subroutine alias does that.
The routine returns a reference to an array in which the elements are aliased as passed in. So to create an array which aliases the slots 2,3 and 4, you would call it as:
my $ar = alias("foo","bar",$v,$v,$v,"baz");
Assigning to any of the slots 2,3,4 of @$ar will change the other two slots as well, which is how I interpret the question.
I might well have misunderstood the question and the problem, as I also don't understand what he needs it for, or rather, what he needs it for prompts different solutions to me.