Ranking columns based on condition in Excel

Hi,
I have a requirement in which I need to get ranking of tax rates based on corresponding store number.

The work sheet will have columns like this

Date, Store, Tax rate, Sales amount, Tax amount,...

data looks like this

02/01/2011, 1190, 6%, 100, 6
02/01/2011, 1190, 7%, 200, 14
02/01/2011, 1190, 5%, 50, 2.5

02/01/2011, 1200, 9%, 200, 18
02/01/2011, 1200, 4%, 100, 8
02/01/2011, 1200, 2%, 150, 3

I need to get Ranking for tax rate as below in another work sheet
The columns like

Store, Tax rate, Tax Rank
Data like.
1190, 6%, 2
1190, 7%, 1
1190, 5%, 3

1200, 9%, 1
1200, 4%, 2
1200, 2%, 3

Please help me to achieve this solution.
Thanks in advance,
Srikanth