How NAT 1:1 netmap over VPN

Hi,

I have problem with configuring NAT 1:1 over VPN connections.

 Mikrotik 10.0.5.1----------  PC_0 10.0.5.2
                  \
                   \--------------------------------------------------
                    \                                                 \
                     \    VPN L2TP 172.40.5.1                          \    VPN L2TP 172.40.6.1
                      --- Router_1 192.168.0.1                          --- Router_2 192.168.0.1
                            / \                                               /\ 
                           /   \                                             /  \
                          /     \                                           /    \
                         /       \                                        PC_3   PC_4
                       PC_1     PC_2                               192.168.0.2   192.168.0.3
                 192.168.0.2   192.168.0.3

What I want to achieve, is ability to connect from PC_0 with PC_1, PC_2, PC_3, PC_4.

The final net map address setup should look like this :

Router_1 172.40.5.1/192.168.0.1
PC_1 192.168.0.2 map to -> 172.40.5.2
PC_2 192.168.0.3 map to 172.40.5.3

Router_2 172.40.6.1/192.168.0.1
PC_3 192.168.0.2 map to -> 172.40.6.2
PC_4 192.168.0.3 map to -> 172.40.6.3

THX for help.

Regards Marcin.