Item summary from multiple Stores

Hi all,

I have a customer with multiple stores that are all individual files that I need to generate an item summary for as a bulk action and export into a excel file, I know this can be done in purchase summary supplier which only gives you the $ amount, but am needing to be able to do it through purchase Item summary. Only way I can see at the moment is purchase (Item summary) and this gives me all items for anything entered into the system over a period of time and no way of itemizing it 

Thanks in advance for any help