Crystal reports- Calculation between two reports

Hi Experts

I have designed a sales and purchase transaction report using crystal reports and i have designed another report for accounting transactions like Excise Duty payable and receivables, Vat payable and receivables, Expenses(like EB, Maintenance) and so on. Finally I added accounting report as sub-report into First Report.

My question is, is it possible to made some calculations between sub-report and main report.

Hope some solutions from you.

By

Kala