Yes this is definitely possible.
Lets say you have a POD file of a car with doors, tires, steering wheel, etc.
If you want to access the tire of the car in cocos3d, you will need the name of the tire node, this should have been set in your 3d editor (maya, blender, etc).
Lets say you used maya and that you have set all four tire nodes names to:
L_back_tire
, L_front_tire
, R_back_tire
, R_front_tire
.
Then you would do this
//load car and all the child nodes of the car
CC3PODResourceNode *car = [CC3PODResourceNode nodeFromFile:@"Car.pod"];
[self addChild:car];
//the car and all its child node (tires,doors,etc.) have been loaded into the scene
//so this is how you would fetch the left tire
CC3Node *leftTire = [car getNodeNamed:@"L_back_tire"];
//do more stuff with that tire her