Yeah it is possible with GSM 0.23x i think. It will be saved in a CNF file.
Try to rename the GSM elf in ... and place it in the first memory card in a boot folder.
You will use the R1 button to launch it at the starting screen.
When you launched the ELF, there is a function to save settings. Try it! (I never did it so i lack experience )
PS: Replace "..." by a "BOOT"+ ".ELF" (Difficult to make more precisely answers cause my account's limitation. It bothers me! -_-')