I am designing  a report in which a Running Balance column adds itself to Debit and subtracts the answer from Credit column on every row. Here in this example I have started calculating from 1st of January. In this case, my Running Balance column will have zero.

 

Now my client wants to have a look at records from 17 January to the end. In that case, my cumulative balance will NOT be zero at first but instead it will calculate cumulative balance for all the dates before 17 January, and present it as the starting balance for 17th of January. I am stuck at this point. How to add all the record before 17th of January and show their Total in a single row. I will be grateful for any help.

I am trying to do that. But the problem is that in my sub-report, there are four calculations of Running balance amongst which I need the last one but it selects only the first one. I have tried to experiment with OnLastRecord but nothing has come out of it.