Lets say that your textbox is named txtDate and your combo box is named cboEmployee. One thing that you don't tell us is if the combo box is bound to a the employee ID (numeric) or the employee name (text), so I'll provide both options. In your textbox in which you want the total expenses, enter one of the following:
(for numeric employee ID)
- =DSum("ExpenseFieldName", "TableName", "EmployeeField = " & Forms!EodF!cboEmployee & " And ExpenseDateField = #" & Forms!EodF!txtDate & "#")
(For text employee name)
- =DSum("ExpenseFieldName", "TableName", "EmployeeField = '" & Forms!EodF!cboEmployee & "' And ExpenseDateField = #" & Forms!EodF!txtDate & "#")
The difference is that text fields must have quotes around the string for which you are searching.
Just make sure to change the field names and the table name to fit what you have.