Sub-Summary problems

[Lucky]

Hi

I have created a report layout that displays individual Job tickets showing there Required Date, Customer, Reference and Spec No. They are Sub-Summarised by the Customer, and also have a Trailing Grand Summary.

What I would like to have is field in the summary definition showing the range of required dates that I searched for in the beginning.

Something like this: " >28/2/2006 <10/3/2006"

Also is there a way of having a Calculation Field in the sub-summary definition that only calculates the records it's found and not the overall total found records just like a summary field works.