DHCP SERVER and relay

Dear all I have this situation:

A central switch without vlan managment serving LAN 10.235.3.0/24.
Two Mikrotik Access point A and B connected to this switch with their ether1 interfaces. Each access point has:

  1. one bridge in which there are ehter1 and wlan1 interface. I need simply to extend 10.235.3.0/24 network via wireless. In the LAN 10.235.3.0/24 I have a dhcp server implemented with a Linux Server.
  2. a virtual AP that implement another SSID wireless for Guest and a dedicated DHCP server leasing ip on virtual AP interface. The dhcp server on first access point lease address from 192.168.0.2-192.168.0.127 and second dhcp server on the other access point from 192.168.0.128 to 192.168.0.254). In this way if a user move from an access point to another in the mean time there is not a new dhcp request he can use previous ip address without overlap.

I would to use one central DHCP SERVER and dhcp relay on each access point. Can you help me to configure it?
i cann’t modify actual dhcp server on Linux installed on LAN 10.235.3.0/24 and then I would to implement:

  1. one dhcp server in one of mikrotik access point for example A leasing ip address on its interface virtual AP. And this is simple
  2. on access point B I would to have only dhcp relay that send request to dhcp server on AP A. But this is the problem. Access point B can communicate with Access point Bthrough the switch and interfaces ether1. The DHCP server on A will answer only on interface virtual AP. I can’t allow dhcp server to lease address on interface ether1 because in my LAN I have the other DHCP server.

In wich way I can add DHCP SERVER on interface ether1 that only answer to dhcp relay and not to all local LAN?
Thanks