how to route port

hi all

Want to know if it is possible to route let say port 2000 to this gateway “y” and port 20001 to gateway “z”

without to change the gateway

thanks
vincent

Request from LAN or from Router ?

if from inside, then routing-marks, if from outside NAT + connection-mark, routing mark

mangle here:
http://www.mikrotik.com/testdocs/ros/2.9/ip/mangle.php

nat here:
http://www.mikrotik.com/testdocs/ros/2.9/ip/nat.php

IS it poseble to give me an idee how to do this

Thanks