In an update query, can’t the criteria be an expression? I’m trying to update certain table fields based on the rightmost characters in another field.

Like this:

Criteria:
(Right([Budgets]![BudgetCode],2)="00")

Update to:
[Budgets]![TotalMDF]/6

Yes the criteria can be an expression. You should have both columns in the QBE grid. The BudgetCode would have the criteria expression and the TotalMDF (or what ever column you are updating) would have the update to expression.

You might want to post the actual SQL if that explaination doesn't solve your problem.