Using FortiGate with private subnets from ISP (MPLS)

Hello all!

I'm starting out with Fortigate, and I’m to figure out how to get the cisco be replaces with a FortiGate..

We have ethernet connections from the ISP, where we establish an PPPoE connection, here we get an private ip with a /24 subnet.

Thats where i get stuck, the connection is part of an larger network and were getting an internal subnet from the ISP (sort of MPLS network). So currently using Cisco, were just configuring the Dialer interface and the Vlan with the same ip/subnet and it matches automatically. Can the same be (easily) achieved with the Fortigate? 

In the Cisco we have configured something like this:

interface GigabitEthernet0 (Connected to ISP) no ip address pppoe-client dial-pool-number 1

interface Dialer1 ip unnumbered Vlan1 dialer pool 1 dialer-group 1 ppp authentication pap callin ppp pap sent-username xx password xx

interface Vlan1 ip address 10.10.10.1 255.255.255.0

ip route 0.0.0.0 0.0.0.0 Dialer1

Any help is much appreciated, Thanks!

Dennis