IPIP tunnel over IPSec Mikrotik - Fortigate600D

There are two devices.
1. Fortigate 600D
2. Mikrotik RB951Ui-2HnD

I need to configure the IPIP tunnel over IpSec.
On the equipment Mikrotik IpSec works in transport mode. IpSec mode can not be changed.
It is necessary transport mode of operation IpSEC.
How on Fortigate to configure IPIP through IpSec?
How to use IpSEC transport mode?
I used this manual http://help.fortinet.com/fos50hlp/56/Content/FortiOS/fortigate-ipsecvpn/GRE_over_IPsec/Config_Overview.htm#Configur3
There is gre, but I tried to do the same for IPIP. Nothing succeeded.
I apologize for my English.