Static Route required

HI,
I have two routerboards, one is at the NOC, and the other at a high site. Both are connected together via a third party wireless bridge.
There is a l2tp tunnel going from one board to the other. The router board at the high site is doing PPPoE on port 3. Port 3 also has and ip on it,10.12.15.1. There is machines connected to the port with ips in the same range.

I can connect to the noc router and connect to the high site routerboard if I type in the l2tp(10.0.103.5) ip using winbox on my pc and connect straight to the routerboard. The routerboard can ping any of the machines on the 10.12.15.0/24 subnet but I can not. How do I static route the 10.12.15.0/24 down to the NOC router so that I can log into it with my windows machine when connected to the noc router via vpn?


NOC ROUTERBOARD

Ether1: 87.x.x.3
L2TP IP: 10.0.103.1
ROUTE: 0.0.0.0/0 87.X.X.1
LAN IP: 10.11.13.1


HIGH SITE ROUTERBOARD

Ether1: 10.11.13.2
L2TP IP: 10.0.103.2
ROUTE: 0.0.0.0/0 10.0.103.1
PPPOE server IP: 10.12.15.1

My windows machine gets 10.0.103.20 when I vpn in.

/ip route dst-address=10.12.5.0/24 gateway=10.0.103.2

On the NOC router