include information already filtered out

Summary

Add a count of incidents assigned to group/accounts already filtered out of a report.

Content

Hi all. 

I have a report that shows a manager all open incidents assigned to their team by using the incidents.assgn_group_id=Logged In filter. It shows various bits of useful information contained within the Contact & Incident tables but what I really want to be able to do is add a column to show whether there are also open incidents assigned to particular Accounts that we use as specialists. An expression is straightforward enough but because those users are not within the same group as the person running the report (and therefore excluded by the filter) I can't quite work out how to