add an ID automatically to URL

i am working on a simple content management system, i have a menu that contains urls and any needed task (controllers), like :

ID title url permission parent_id ....
1 home / any 0
2 login /user/login unauthenticated 0
...
10 task1 /controller/task1 any 0
11 task2 /controller/task2 any 0
12 task2_alt /controller/task2 any 0

my problem is :how i can add page_id or menu_id to url using routes so in every get that id?

i want to use that id in my template class for adding widgets to page, ex. in menu_id : 11 i have widget_a , and in menu_id : 12 widget_a and widget_3

in face controller/task2 is same in two menu_item but page_id of them id different,

i need something like this in routes :
user type "site/ index.php/ 12/ controller/ task2/ bluh/ bluh" that 12 is a number (id of menu_id)

ressan.ir
CI is nice