Hi Hobbit,
Only static protocols can be run on the management interface. You can try the following way:
1. On the AR, configure a static route with the next-hop pointing to G0/0/0 of NE40E _01 and import the static route to IS-IS.
2. On NE40E_01, configure a static route with the destination address being U2000 and the next-hop being the AR. Import the static route to the dynamic routing protocol so that 02 and 03 can learn the static route.