array indexes as arguments to a function

please CC me, as I am on digest. ------------------------------------------------------------------- say I've got a class that stores the cookie/get/post vars. I want to retrieve say one of them. Say, that post vars come back from browser as: POST["var1_arr"]["dim1"]["dim2"] they are stored in object->post_vars["var1_arr"]["dim1"]["dim2"]; object->post_vars["singleton"]; I have the function class->get_post_var($index_arr){

      return correct, processed post var;

} How can I get the function to return an arbitrary depth into the post vars array? i.e. EITHER return $this->class_user_input_processing_function( $this->post_vars, $index_arr); Where $index_arr contains either: $index_arr = array("var1_arr","dim1_value", "dim2_value"); -or- $index_arr = array("singleton");