That's kind of close to what I ment, but what I was thinking was for example swapping the Jamaican league in for the Hong Kong League, or the Nigerian for the Swedish via the traditional method of swapping and renaming on the editor.
I was curious if doing so would mean the winner of the new 'Jamaican' league would play in the CONCACAF continental competition or the Asian equivilent because the Jamaican league was based on the HK league and it was hardcoded that the winner played in that.
I couldn't find reference to it under any other topics but I'm certain loads of people must have done this and know the answers.