Shipping cost as percentage of order amount?

[duds]

Hi All

 

I've spent days now searching the forums, using different key words etc, but to no avail. Now I have toa sk for help:

 

I have 3 zones, UK, Europe and Rest of the WOrld.

 

UK is free shipping, not a problem.

 

Europe and the rest of the world, I want to add a percentage of the order value as shipping cost for these two zones, is this possible? Zone 2 (Europe) 15% of the ttoal order amount and rest of the world 20%.

 

My store is live and has been for 4 years now and I don't want to start crashing it by experimenting, especially when there are buying customers on line.

 

Can any one give me a quick pointer as to wether or not I can just add weight say, 99:20% to that table rates?

 

Cheers

Duds