Port Forwarding to a PPTP client

Hi,
I want to forward a tcp port (80) to a pptp remote client.
The reason why I want this setup is because the ISP on 2nd Mikrotik can’t use port forwarding as it uses it’s own NAT… No public IP!

Here is my setup:

1st Router (PPTP Server)
[ISP: 24.212.25.98] → [1st Mikrotik: 192.168.1.1]

2nd Router (PPTP Client)
[ISP: 10.12.13.14] → [2nd Mikrotik: 192.168.111.1]


I want to be able to contact a web server behind 2nd Mikrotik (192.168.111.10)

Note that all routes are already setup, and all clients can reach/ping each other from both Mikrotik network.

How can I accomplish this?

Thanks everyone!

(Sorry for my English!)