Restore from offsite private cloud with no direct connection

Hi All.

I have a question regarding restore of data which resides on a offsite private cloud where clients have no access.

Setup is:

On prem Client network with servers in backup.

→ Firewall in between with port open for backup traffic.

On prem Backup network with MediaAgents and storage.

→ Firewall in between with port open for aux copy data.

MediaAgents with offsite private cloud storage containing Aux copies of client data.

Clients do not have access to the offsite MediaAgents/copy, so my question is, how do I make a restore of data from the offsite cloud, when the On prem clients and the offsite MediaAgents cannot talk to each other directly? Is it possible to route restore traffic via the on prem MediaAgents acting as a proxy some how? Would the network gateway via outgoing routes be the solution? 

Any suggestion would be appreciated.

Thanks for helping.

-Anders