Hello! You can use this function :

sub arrayInsertAfterPosition
{
  my ($inArray, $inPosition, $inElement) = @_;
  my @res         = ();
  my @after       = ();
  my $arrayLength = int @{$inArray};

  if ($inPosition < 0) { @after = @{$inArray}; }
  else {
         if ($inPosition >= $arrayLength)    { $inPosition = $arrayLen
+gth - 1; }
         if ($inPosition < $arrayLength - 1) { @after = @{$inArray}[($
+inPosition+1)..($arrayLength-1)]; }
       }

  push (@res, @{$inArray}[0..$inPosition],
              $inElement,
              @after);

  return @res;
}

my @tab = qw(A B C D E);
my @res = ();

@res = arrayInsertAfterPosition (\@tab, -1, 'Test');
print join(', ', @res) . "\n";
@res = arrayInsertAfterPosition (\@tab, 0, 'Test');
print join(', ', @res) . "\n";
@res = arrayInsertAfterPosition (\@tab, 1, 'Test');
print join(', ', @res) . "\n";
@res = arrayInsertAfterPosition (\@tab, 2, 'Test');
print join(', ', @res) . "\n";
@res = arrayInsertAfterPosition (\@tab, 3, 'Test');
print join(', ', @res) . "\n";
@res = arrayInsertAfterPosition (\@tab, 4, 'Test');
print join(', ', @res) . "\n";
@res = arrayInsertAfterPosition (\@tab, 5, 'Test');
print join(', ', @res) . "\n";
[download]

The result is :

Test, A, B, C, D, E
A, Test, B, C, D, E
A, B, Test, C, D, E
A, B, C, Test, D, E
A, B, C, D, Test, E
A, B, C, D, E, Test
A, B, C, D, E, Test
[download]