A typical Open Invoices Report looks like this:

With QODBC the same report can be generated using stored procedure reports like this:

sp_report OpenInvoices show Text, Rowdata as Type, Blank, TxnType, Date, RefNumber as Num, PONumber,
Terms, DueDate, Aging, OpenBalance parameters DateMacro = 'Today'

All the predefined DateMacro options available to you are:
|All|Today|ThisWeek|ThisWeekToDate|ThisMonth|ThisMonthToDate|ThisQuarter|ThisQuarterToDate
|ThisYear|ThisYearToDate|Yesterday|LastWeek|LastWeekToDate|LastMonth|LastMonthToDate|LastQuarter
|LastQuarterToDate|LastYear|LastYearToDate|NextWeek|NextFourWeeks|NextMonth|NextQuarter|NextYear|

You can also access unpaid INVOICEs directly using the Invoice table and the IsPaid filter like this:

select CustomerRefFullName, TxnDate as Date, RefNumber as Num, PONumber, TermsRefFullName as Terms,
DueDate, BalanceRemaining as OpenBalance from Invoice
where IsPaid = 0 order by CustomerRefFullName, TxnDate

Depending on your QODBC optimizer settings, you might need to do this:-

select CustomerRefFullName, TxnDate as Date, RefNumber as Num, PONumber, TermsRefFullName as Terms,
DueDate, BalanceRemaining as OpenBalance from Invoice calldirect
where IsPaid = 0 order by CustomerRefFullName, TxnDate

instead to see the true open balance in real time.

See also: How do I run a Customer Balance Detail Report?