This help page explains our shipping calculation settings:
We don't have any way to query Createspace directly to obtain their exact shipping rate for each order, so you'd need to set up shipping calculation at our end to at least roughly match their shipping rates. You may want to see if Createspace can provide some documentation summarizing their shipping rates by country.
When you go to E-junkie Seller Admin > Cart Shipping Settings and click Next, you can create Shipping Rules. You would probably create one Rule to cover All Countries (this covers all of your chosen Shipping Destination countries, back on the first screen of Cart Shipping Settings), then make additional Rules for specific countries that would override the Rule for All Countries. I'm guessing these Rules would probably use the "Price per unit" calculation method, if Createspace charges a per-book flat shipping rate.