configuring price column to include a shipping calculation

Within my site, on each item's detail page, I have the price displayed including shipping (which is a calculation based on cubes and cost per cube), calculated in the code using math functions as follows.

<?php
$x = $row_rsDetails['price'];
$y = $row_rsDetails['ShippingCubes'] * $row_rsDetails['CostperCube'];
$a = $row_rsPackageShipping['ShipSum'];
$b = $y + $a;

echo bcadd($x, $b, 2);
?>

I need to be able to configure the price column of my add to cart object to use this calculation as the price, rather than the price binding from my database. Can someone guide me as to how to configure my price column to use this calculation? Thanks in advance

in the add to cart button, set the price to be updateable from a hidden element, then set the value of the hidden element to use your formula.

Just so I can be completely clear and clean in my coding, I have added the following to my Add to Cart "form" element

<input type="hidden" name="TotalPrice" value="<?php
$x = $row_rsDetails['price'];
$y = $row_rsDetails['ShippingCubes'] * $row_rsDetails['CostperCube'];
$a = $row_rsPackageShipping['ShipSum'];
$b = $y + $a;

echo bcadd($x, $b, 2);
?>" />

and in the header within the Add to Cart object, I have added this coding

$ATC_itemPrice = "".((isset($_POST["TotalPrice"]))?$_POST["TotalPrice"]:"") ."";// column binding

Is this all I need to do? Does this look correct as far as you can tell?

that looks correct.

I would probably change the form element code to:

<?php
$x = $row_rsDetails['price'];
$y = $row_rsDetails['ShippingCubes'] * $row_rsDetails['CostperCube'];
$a = $row_rsPackageShipping['ShipSum'];
$b = $y + $a;

$calculatedPrice = bcadd($x, $b, 2); 
?>
<input type="hidden" name="TotalPrice" value="<?php echo $calculatedPrice; ?>" />

awesome, works perfectly, thanks Jason!