Questions about creating regional leagues

[noobcake]

I'm getting FM13 soon and after messing around in FM12 editor I want to try create something a bit more complex.

I'm probably gonna wait for the big update with winter transfers before starting but it's would be nice to have a good idea of what I'm about to do ahead of time.

Basically, my idea is to take several groups of European nations whose leagues are kinda bad and group them up into one league that would actually be able to attract players and be more fun to play. So far I'm thinking on grouping former Yugoslav countries, some Central Europe countries (Switzerland, Austria, Hungary, Czech Republic, Slovakia), Scandinavia and the Baltics + Poland and Belarus.

I do not want to change players, clubs, national squads or youth intakes at all. I just want to change the league structures. I'd like to ask some of the more experienced editors what would be the best way of accomplishing that.

I'm wondering how would I make this work? I've managed to create one in FM12 using an imaginary nation(I'm guessing hosting at one of the existing nations would've been smarter because I now have an additional crap national team) but this still sends clubs from the remnants of the constituting nations into Europe. Is there a way of integrating the leagues without messing up the European competition qualifiers or would it be better to simply rebuild continental competitions to better suit this system (maybe even make these competitions continental)?