How to apply condition at header level instead of item level in BEx?

Hi,

I have a query in which Item status and a certain amount is getting displayed against each accounting document number.

Here I want to display those document numbers (header) only which are open and whose amount field value is greater than 0.

Say I have a document number 1800007115 which has been closed so its item status is C and since it is a multiprovider based on infocubes it also has the same documnet number with earlier status as Open .So even though the item is closed it is getting displayed in the report since the condition is working at item level.I had done some trial and error by changing something in the Free characteristics and it had worked.But then the query got corrupted and had to be deleted.So pls help.

Regards,

Shalaka