"reverse connection"

I have successfully activated a kit with eNB=Nova227 in NAT mode
and CPE=ID06 also in NAT mode.
It is installed in a private LAN ( and works well, because any UE (PC) connected via ethernet to the CPE,
can ping any device on the LAN and navigate internet with browser via LAN gateway.

But a customer needs also initiate a TCP connection from a PC on the LAN (where stay the eNB),
to the network of the CPE (, connecting a slave PC ( on such subnet.

In eNodeB I see other LGW modes as Router and Bridge, but none of them seems solve the need of such “reverse connection”.
Can you advise the proper LGW mode and/or routing configuration to achieve this connection ?