Outlook 2010 - Disable the purge button from within Recover Items

Hi,

As the title states, how can I disable the "purge" option from within "Recover Deleted Items" option within Outlook 2010? 

I know that I can enable "Single Item recovery" from the exchange 2010 side, but this seems like a far simpler way of identifying deleted items that may be required from a legality point of view.

I am unable to apply a retention policy to an archive mailbox, therefore this seems like a simple solution.

Thanks for you time