vpn over internet DHCP problem

hello guys

so i got 3 mikrotik boards installed in my networks
we installed one as main and the athers as Remote

Made all the configration oky so the remote can conect to the main board over pptp with no problems
and made the network as EoIP tunnels on the 3 boareds

the Ip range for my networks is 192.168.0.0/22

so it gose like

192.168.1.1 for the main board and the rest for its network
192.168.2.1 for the First remote and the rest
and 192.168.3.1 for the second remote

tell now every thing going oky

buy my problem is in DHCP server i Need to put the IP as static so i put the ip’s with there mac’s and it works fine

what i wannt is to do it that the Main board gives the DHCP without puting it static like it just give every divce in the network an ip and the main is the only one that can do that

any one can help me to fix these think i done the hardest part yet stuck in these

forgot to say that the ip binding is only on the main network the remotes works fine without any need for ip bind with macs