A few ways you could achieve this:
1. Do the calculation in the SQL and sum that field, like so:
SELECT Quantity, Amount, Quantity * Amount As TotalAmount FROM MyTable
Then just use the TotalAmount field in your Detail row and sum it in the footer.
2. Create a second Dataset that calculates the total for you and use that in your footer instead of a sum:
=Sum(Fields!TotalAmount.Value, "MyTotalingDataset")
3. Do it using custom code. Right-click on the Layout space choose Properties and click on the Code tab. Put in the following code:
Public Dim TotalAmount As Double = 0
Public Function CalculateRowTotal(ThisValue As Double, ThatValue As Double) As Double
TotalAmount = TotalAmount + (ThisValue * ThatValue)
Return ThisValue * ThatValue
End Function
On the Detail band, make the column where you sum the field have this expression:
=Code.CalculateRowTotal(Fields!Quantity.Value, Fields!Amount.Value)
This will execute the code above and do your calculation plus calculate the total sum in the process.
The Footer band displays the total sum so the column has the expression:
=Code.TotalAmount
And you're done. Just be careful because you aren't guaranteed the order in which your code will execute and for some reports it will execute the footer first (for example, if you use the Sum of the rows in the Detail band) which would make the total zero as the Detail band calculations haven't happened yet, but for the general case this should work.
If I were you, I would create a new calculated field which would hold the sum of all your Shipped Data (1's) not just the sum of all your data (1's and 0's).
After that, it should be as simple as putting in the expression that subtracts your calculated field from the Sum of your table2 field.
Best Answer
Use a group footer, not a table footer. (If you open the group properties window from the group's right-click menu, you'll see checkboxes to include a header and footer there. Not the easiest thing to find if you don't know where to look.)