Combine tax categories

Hi

Thanks for this wonderful plugin. Need your help in resolving a problem.

I have different tax categories like 5%, 12%. Usually an order consists of multiple tax categories.

While taking report I want to combine the tax and total amount for each tax category for a order

Eg: For an order consisting 4 products. Two with 5% tax and another two with 12% tax.

Tax-category 5% : 500Amount (Product1-300 + product2-200)
Tax-category 12% : 600Amount (Product3-500 + product4-200)

I like to create report like this.

OrderNo Tax-category Taxable-value Taxvalue TotalAmount Total-Tax
1 5% 500 25 1100 97
12% 600 72