Displaying Tax Subtotal on Quote Template

Displaying Tax Subtotal on Quote Template

I have spent a lot of time customizing the Quote template to our needs, and overall I'm happy with it, but I'm having a problem with the way it displays tax.

We frequently apply tax to some line items, and not others. No problem in Zoho. But when I try and display a tax subtotal, I'm stumped. The ${Quotes.Sub Total} field displays the total of all line items, including tax. What I need is:

1. The total of all the tax applied to the individual line items.
2. The total of all the line items, without tax.

The ${Quotes.Sub Total} adds the two above together, which is fine, but I also need them broken out. I can display the individual tax on line items on the template.. is there a script I can use to add them together?

The ${Quotes.Tax} field is useless for our purposes, as it appears to only display the tax that is universally applied to all line items (at the bottom of the Quote input page). We rarely apply tax to everything.

Please help! I'm loving Zoho, but this is critical for our use of the Quotes module. And I would certainly think it would be an issue for others as well.