PPTP tunnel inside OVPN

Hi,

I have problem with PPTP tunnel setup.
My setup looks like this:
Capture

I am connected via OVPN (vtun0) to my university network. The next step i want to do is to setup PPTP connection with one of the routers inside university network. I`m trying to approach this by simply creating VPN connection on win10 VM (10.1.3.129).
I have configured source and destination NAT, as well as routing (in previous setup i had one more router between vtun0 and win 10 vm),
I attached NAT config below. I appreciate any help, that could help me solve me this problem.

interfaces {
    ethernet eth0 {
        address dhcp
        description INTERNET_BRIDGE
        duplex auto
        hw-id 00:0c:29:ce:82:34
        smp-affinity auto
        speed auto
    }
    ethernet eth1 {
        address 10.1.3.254/24
        description VMnet3_GATEWAY
        duplex auto
        hw-id 00:0c:29:ce:82:3e
        smp-affinity auto
        speed auto
    }
    ethernet eth2 {
        address 10.1.10.1/24
        description VMnet10
        duplex auto
        hw-id 00:0c:29:ce:82:48
        smp-affinity auto
        speed auto
    }
    loopback lo {
    }
    openvpn vtun0 {
        mode client
        openvpn-option "tls-auth /config/auth/ta.key 1"
        openvpn-option "--cipher AES-256-CBC"
        openvpn-option "--remote-cert-tls server"
        openvpn-option "--key-direction 1"
        openvpn-option --auth-nocache
        openvpn-option --nobind
        remote-host ovpn.agh.edu.pl
        remote-host 1194
        tls {
            ca-cert-file /config/auth/ca.crt
            cert-file /config/auth/client.crt
            key-file /config/auth/client.key
        }
    }
}
nat {
    destination {
        rule 10 {
            inbound-interface vtun0
            translation {
                address 10.1.3.129
            }
        }
    }
    source {
        rule 100 {
            outbound-interface eth0
            source {
                address 10.1.3.0/24
            }
            translation {
                address masquerade
            }
        }
        rule 101 {
            outbound-interface eth2
            source {
                address 10.1.3.0/24
            }
            translation {
                address masquerade
            }
        }
        rule 102 {
            outbound-interface vtun0
            source {
                address 10.1.3.0/24
            }
            translation {
                address masquerade
            }
        }
    }
}
policy {
    route-map CONNECT {
        rule 10 {
            action permit
            match {
                interface eth2
            }
        }
        rule 11 {
            action permit
            match {
                interface eth0
            }
        }
    }
}
protocols {
    ospf {
        area 0 {
            network 10.1.10.0/24
        }
        parameters {
            abr-type cisco
            router-id 10.1.10.1
        }
        redistribute {
            connected {
                metric-type 2
                route-map CONNECT
            }
        }
    }
    rip {
        network 10.1.3.0/24
        redistribute {
            connected {
            }
            kernel {
            }
            ospf {
            }
            static {
            }
        }
    }
}