"hybrid" nav disc - brazil

We imported a '10 Escalade from the US and so far we've been unable to use the car's navigation b/c GM does not carry the dvd containing maps of Brazil for the system. I even tried to create a "hybrid" disc my replacing the ALLDATA and INDEXDAT and IDX folder with data of Brazil from a Land Rover disc and readding the other files from the original disc, but when I insert it in the system, it keeps saying repeatedly that "the disc is not a nav disc". Is there any way I could create this "hybrid disc"?? Is there any way I doulc "unlock" the system and allow it to run a Land rover dvd??

Thanks