Creating .rtf invoice template with myltiple tax lines

Hi,

I have created an .rtf invoice template for use in the US.  Is there anyway to get the multiple rates of tax to be split on the invoice based on the below example:

Type                         Rate %

STATE          NY       4.00

COUNTY      NY       0.00

CITY             NY      4.875

The problem I have is the XML field is '<INV_TAX_RATE>' for each of the rates.

Thanks

Jon