If you are getting the data from a stored proc, have the proc do the calculations.

 

Otherwise, I would set a formula in the group footer(grouping by date it would appear) and I would sum the credit and debit and would update a shared variable with the new balance.  I would then display the new balance in the group header.  The first balance could be initialized from the data or from a parameter if it is not in the data.

 

Hope this helps in some way.

 

For the detail section, the one that would most of the work, the first line would be shared numbervar x; then you can access this variable with statements that would add to it x := x + {field name}.   I like to end my formula with "" as that will suppress any output that i don't want seen. Finally, drop the formula on the detail line...if you wanted a running balance, leave off the "".

 

In the group header, there would be something like shared numbervar x;

local numbervar lx :=x;

x:=0;

lx....

 

This would display the value.  Drop it on the header group where you want it displayed. 

 

Hope this helps