A safearray can only hold one type at a time which means that it can either be an array of integers or an array of reals.
To bypass that you can make an array of Variants. A Variant in essense is a discriminated union and wraps the actual type, thus in an array of Variants you can have mixed data types.
my $array_size = Win32::OLE::Variant->new(VT_I4|VT_BYREF, 20);
is not correct since this is asking for an array of Ints
I would go for :
my $arr = Variant( VT_VARIANT | VT_ARRAY, 25);
it's 25 elements right?
and also I don't think that you can combine VT_ARRAY with VT_BYREF.
After you get the array of Variants back you can iterate through the elements and check their underlying type with the Type() method and then go on to extract the values