Iptables source and destination based on mac-address

I use LuCI Statistics to measure some stats regarding the router and its use. I also collect internet usage data through the use of iptables. The command that I use for this is similar to following for every user that I track for usage:
iptables -w -A TRAFFIC_ACCT_IN --dst -m comment --comment "user_1_in"
iptables -w -A TRAFFIC_ACCT_OUT --src -m comment --comment "user_1_out"

Now for this to work I need to add static IPs to the DHCP and then the rules work otherwise they dont. Is there a way to use MAC addresses instead of static IPs to perform the above marking? Thanks