How to properly add tax of shipping costs?

Hi there

In my country we have 2 taxes, 8.5% and 20%. The postage goes in 20% tax.

Now I have a shopping cart and let's say we have postage 2 €. That is total, postage + 20% tax. So I added a shipping rule of flat rate at 1.67 €.

What I need to do now is to say e-cart this postage acts like an item or something, because I have to add the 0.33 € to the taxable total of 20% tax. Using the checkbox to include postage to taxable total didn't work, maybe because we have 2 tax rules, how would ecart know I need to make a tax added to the 20% rule?

I can "hack" e-cart rule to manually add the 0.33 to the sales tax, but because we have 3 postages (I was talking of 2 € just for the example), I can not make that a flat rule. The worst part is if I mungle with tax in eCart1_VB.asp and add the shipping totals to the rule manually every time I open the ecart GUI my postage rules are rewritten, so this is not a good option.

How is the proper way to do this? There must be a way to say to the tax rule I want my postage rules to be included in tax and in which tax? Can I make a calculation for this?

This is puzzling me for 6+ months, I have "solved" this by manually tweaking the tax rules, but it has done more bad than good as I have to copy paste back my shipping rules every time I change something.

The problem I see lies in the fact I can not use the TaxableTotal as in my country I have to state separately the 8.5% tax and the 20% tax, so I need 2 rules which takes values from my item price * tax totals, not the taxable totals. Taxable totals work ok only if you need total of paid tax, but I need 2 different taxes to show in cart and the postage must be added to one of them (20% one).

Thank you for your help

Yours

Jernej

PS - I have eCart 4.5.2 with ASP