Drillthrough Report with count

Hi,I have an SSRS report with a drillthrough table on it. There are 12 columns, each column is expandable to another level. Depending on which columns expanded, I would like a "count" column at the end of the table that shows the number of rows in that group, [img]http://imgur.com/ivRb0kX[/img]http://imgur.com/ivRb0kXSo, if I was to collapse the group in Col1 upto UK, the rowcount would be of all the counties/towns/roads in the UK. CountRows seems to work fine, but I can't get it to change its scope based on the group expanded.Thanks,Andrew