sub sub_alias (\&;$) {
  my ($func, $ix) = (@_, 0);
  sub { $func->($ix, @_) };  # that's sub { ... }'s @_, not sub_alias's @_
}

*foo = sub_alias &bar, 1;
*blat = sub_alias &bar, 2;
*gunk = sub_alias &bar, 3;