AX 2012 SSRS, need VS expression which sum the amount of a calculated by expression field.

Hi everyone. I am trying to add sum, in a text box, of the amount calculated in another field.

Here is more detailed explanation of the scenario and the problem. In my report i have the following fields - Qty, Box quantity, Quantity in one box and Remaining Qty. I have the data for Qty (the quantity of the products in the shipment) and Quantity in one box (it is constant of the products, that fit in one box). Then i have add-ed the following expressions to calculate the Box quantity and the Remaining quantity:

- Box quantity

               = IIf (Fields!qtyInOneBox.Value<=0,0,Fields!Qty.Value/Fields!qtyInOneBox.Value)

- Remaining quantity 

               = IIf (Fields!qtyInOneBox.Value>0, Fields!Qty.Value Mod Fields!qtyInOneBox.Value,0)

Now what is my problem. I need to add two text boxes which contains the sum of the two calculated expressions. One must contain the sum of the boxes in one shipment, the other must contain the sum of the remaining quantity (the quantity that doesn't fit in the boxes)

I am looking forward to your replies.

Thanks in advance.