move out of stock products to the end of the list

[@ntonio]

Hi
I need to move out of stock products to the end of the list, without depending on sorting in a category. Wherever is costumer sorting products by product sku, price, alphabet, ect. out of stock products must be at the end of the list.
thanks for any pointers you maybe able to give
Joomla 2.5 VirtueMart 2.6.12
Thanks, Anton

[@ntonio]

No suggestions?

[GJC Web Design]

sounds like a core hack because u would have to do it before the pagination comes into effect