Remove duplicate incidents from a report

Content

Is there a possibility to remove duplicate incidents from a report (like the "remove duplicates" function in excel)?

I have created a report to check which companies still send letters to us by postal mail (attachment added to incident by agent).

The report has the following columns:

• time (fattach.created)
• reference number
• contacts_last name

And the following filters:

• date (fattach.created)
• transactions.transtype in list assign, opt-in
• transactions.source_hierarchy=cx console
• fattach.username=complex expression=2011

the output shows what I want, but some incidents show up more times with exactly the same transaction time, although the transaction (adding an attachment from the right now console to the incident) has only occured once. I now want to remove these duplicate incidents (it helps to add a column with a count-funtion, but then it seems that more attachments were added to the incidents than there actually are).