formula help for Calculating Running Totals actual costs versus baseline funding

[kmims44]

Ok I'm sure this is easier than I'm making it but I'm having a mental block. I have a table called "ContractCostSummaryT" with the following fields:
Original Target Cost
Negotiated Changes
Contract Type
Start Date


End Date
ContractName
ContractValue
PeriodOfPerformanceDays(calculated from End Date-Start Date)
PeriodofPerformanceMonths(Calculated from POPDays)
SLIN(lookupfield from table SLINRefT)

I have another Table "ContractBudgetT" with the following fields:
Date
BudgetedHours
SubTotalofBudgetperMonth
ActualHours
ActualMonthlyCost
ContractName(lookup field from the above referenced table)
WBS(lookup field from table WBSReftT)
BudgetvsActualperWBSperMonth(calculated from SubTotalofBudgetperMonth-ActualMonthlyCost)
SLIN(lookup field from SLINRefT)

Now...What I want to do is 1. On a form automaticly populate a entry box for each month of the PeriodofPerformanceMonths 2. Calculate a running grand total for the contract Actual costs and the Budgetcosts based on what day it is 3. Calculate a running total for the actual costs and budget costs based on the WBS and current date 4. Calculate a total that is the ContractValue(from ContractCostSummaryT) - Sum(Contract Actual Costs) based on the current date

ANY and ALL help setting up the formulas to do this would be greatly appreciated!!

[June7]

For starters, Google: SQL running sum

Review:
http://www.1keydata.com/sql/sql-running-totals.html
http://allenbrowne.com/subquery-01.html
https://www.accessforums.net/queries...ing-25488.html

Textboxes on report have a RunningSum property.