You won't get into AVR with DnD only
Changing the script is not that hard after a bit or reading:
http://wiki.codeblocks.org/index.php?title=Wizard_scriptsOnly one line has to be changed and I have given the exact content. (search for Wizard.AddCompilerPage in the AVR wizard script and replace it by the one mentioned)
When the script is asjusted, you need to add the avr-gcc to codeblocks compiler configuration:
In the compiler and debugger settings panel select GNU GCC Compiler. Click on "copy" and give it a name (for example "GNU AVR GCC"). In the Toolchain executables-tab point to the directory where you installed avrgcc and adjust the names of the executables.
(something like avr-gcc, avr-g++, avr-g++, avr-ar, avr-gdb or avr-elf-gcc, evr-elf-g++ I don't know the exact names from the CrossDev package.) The fileds of the "resource compiler" and "make programm" can be left empty.
regards