Shipping based on Cart Total

I hope someone can help me with this. I am not a programer so this is a bit over my head. I understand the basics for designing and was trying to find some documentation on the shipping for eCart. But here is what I am trying to accomplish for my shipping/Handling charges to my cart.

I want the shipping to be charged from a matrix for the total of the cart and have the shipping be determined on whether the shipping needs to be domestic or international.

The shipping matrix would look like this:

Domestic
0.00 - 20.00 = $5.95
20.01 - 50.00 = $7.95
50.01 - 100.00 = $10.95
100.01 - 150.00 = $12.95
150.01 - 200.00 = $14.50
200.01 - 250.00 = $16.50
250.00 and up = 7.5% of cart total

International
0.00 - 50.00 = $12.00
50.01 - 100.00 = $15.00
100.01 - 150.00 = $18.00
150.01 - 200.00 = $20.00
200.01 - 250.00 = $24.00
250.00 and up = 10% of cart total

If anyone has any ideas I would be much appreciated.

Thanks,
Bknvc