trouble adding [charges] to calculation

In my calculation column I am trying to add [Charges] into the calculation.

I have the following : [myvat] + [TotalPrice] + [Charges] - myvat is another calculation

This does not work, I just get a blank screen. If I change it to [myvat] + [Totalprice] it works fine but then leaves out the charges.

I have tried different ways of typing [Charges] like Charges, "Charges", ([Charges]) yet nothing works.

I can't just use the default total you get with Ecart (GrandTotal) as it doesn't include [myvat].

Is there anyway to add CHARGES to my calculation and get it to work?

I would really appreciate any help.
Many thanks.

A calculation is on a per item basis and can only include values from the cart columns. It will not be possible to include other charges from the cart in a calculated column. You could store the total vat for each item with a new column in the cart, then you could setup a charge rule that will be based on the subtotal of this vat column in your cart. Please explain a little about how you would like this working in the end and we can give you some pointers on how to get it that way.

Hi. What I have decided to do is the following:

<?php $vat = $pass->TotalColumn("myvat");
$delivery = $pass->GetCharges();
$subtotal = $pass->TotalColumn("TotalPrice");
$vatdelivery = $vat + $delivery + $subtotal;
echo number_format($vatdelivery,2);
?>

It works great accept for when I use Universal email to send the mail with this code in it. Instead of showing the $vatdelivery amount it is blank. Should I try get this into a session variable or something?

That is exactly what you should do, storing this value in a session variable will ensure that you can get access to it in the email. Sometimes the scope of variables can be a tricky thing in php, but luckily using the session variables is easy way around this.