what you mean unlock code, if you mean the screen lock all you have to is connect to itunes and it will unlock it for you and you can ither turn the lock off from there or use your own lock code.
or you can reset your ipod by pushing the hold button on then turning off and holding in menu and the middle circle at the same time for about 10 sec it wont always work first time took me like 5 but hope it helps ya