Visual Basic 6 (VB6)

I am developing application with vb. I have two Access tables named
Cont and FundEx respectively. The fields for the Cont are Date, Accno, and Amount and FundEx are Date, Accno, Payee and Amount. The two tables are linked by Accno

Cont table accumulates contributions from members into the various contribution accounts
FundEx records expenditure as they occur into their respective accounts. Each expenditure recorded updates its corresponding account in the contr table by reducing its corresponding account in the Cont table.

Pls I need SQL query statement:
1. To update Cont table each time expenditure is recorded.
2. To calculate the balances of the each contribution account at any point in time.

Any help will be greatly appreciated

Thanks