This is my network scheme.
What I'm trying to do is access CPE (sxt lite5) via winbox from my pc.
Nano stands for ubiquiti nanobridge
CPEs are in the same network, connected to each Ap. (Sorry, for the picture, it's not so clear)
each Access Point is connected to one dsl separately. (e.g Ap3=>isp1, Ap4=isp2)
isp1 & isp2 are my 2 internet gateways (192.168.8.1 & 192.168.9.1)





How to set ip routing and achieve that?

What is isp1 and isp2? To whom belong ap3 and ap4? Are the cpes also within your network?

you're right, I forgot to explain that.
#Edited first post

i assume you dont have control at all on isp 1 & isp 2 router, i think the easiest way to access your SXT is by creating VPN between each SXT and your router

http://wiki.mikrotik.com/wiki/OpenVPN_C ... ep_by_Step

other scenario is, you need to check if your gateway ip, as you said 192.168.8.1 & 192.168.9.1, connected to AP LAN ip 192.168.8.10 and 192.168.9.10. (on the same subnet)

if it so, then just
#AP3
/route add dst-address=192.168.30.0/24 gateway=192.168.8.10
#AP4
/route add dst-address=192.168.40.0/24 gateway=192.168.9.10