How can i start my script when mikrotik start?

How can i run my script when mikrotik start? i cant find this option. My trouble in next: I have two connections to ISP and two dynamical addresses for PPPOE interfaces. Each account have bandwith 512 kbit/s and i want to join it in one 1 mbit/s connection. For it i want to use this manual http://wiki.mikrotik.com/wiki/Load_Balancing, but this shema use statical IPs for gateways. I have two dynamical ips for gateways and can not use this... On mikrotiks start, system have to write global variables my pppoe interfaces ip`s instead of statical ip addresses.

:global smart-ip[ /ip address get [/ip address find interface=pppoe-smart] address ]
:global pppoe-out1-ip[ /ip address get [/ip address find interface=pppoe-out1] address ]



/ ip firewall nat 
add chain=srcnat connection-mark=odd action=src-nat to-addresses=smart-ip \
    to-ports=0-65535 comment="" disabled=no 
add chain=srcnat connection-mark=even action=src-nat to-addresses=pppoe-out1-ip \
    to-ports=0-65535 comment="" disabled=no 
/ ip route 
add dst-address=0.0.0.0/0 gateway=smart-ip scope=255 target-scope=10 routing-mark=odd \
    comment="" disabled=no 
add dst-address=0.0.0.0/0 gateway=pppoe-out1-ip scope=255 target-scope=10 routing-mark=even \
    comment="" disabled=no 
add dst-address=0.0.0.0/0 gateway=pppoe-out1-ip scope=255 target-scope=10 comment="" \
    disabled=no

For this shema i want to start my scripts on system start and update globall addresses of my PPPOE interfaces on interface change ip address.

Sorry of my english.

Set start-time to startup. From the manual:

“If scheduler item has start-time set to startup, it behaves as if start-time and start-date were set to time 3 seconds after console starts up.”