Problem in making url to rails path dynamically

Question

I have a url like

http://localhost:3000/admin/users

i getting admin/users this by using controller.controller_path

Now i want to convert this admin/users in admin_users Finally i have change to rails path using

eval "admin_users_path"

Problem: Sometimes admin path not come. I want to made dynamic path for that. means it can convert all the url to valid path.

Please give an idea for that... thanks