Not 100% sure that was what he was asking.
I understand you want to use the gcc compiler that came with wxDevCpp with Code::Blocks? That is possible without any special changes. The only thing that you will possibly have to do is specify the path that points to the compiler.
If you want to use the Form Designer component with Code::Blocks, no, that does not work. But there is wxSmith as Game Ender pointed out, and using this will of course not destroy Form Designer.