how to make nginx hit multiple urls when a specific url is hit

Dear community,

How to configure nginx such as when a specific url is hit on the server, multiple urls are hit by the server?
This would be a trick for me to trigger multiple RESTful actions simultaneously, as my client can only hit one url.
I would like not to configure an advanced REST server for this and hope nginx can do the trick.

E.g.:

When
http://nginx_server:81/open_shutters
is hit

nginx should hit the following urls:
http://10.0.1.101/roller/0?go=to_pos&roller_pos=95
http://10.0.1.102/roller/0?go=to_pos&roller_pos=70
http://10.0.1.103/roller/0?go=to_pos&roller_pos=70
http://10.0.1.104/roller/0?go=to_pos&roller_pos=60
to trigger some RESTful actions.

Thanks,