hotspot@address lists

I have hotspot and usermanager with 300+users
Is it feasible that when a user logs into a hotspot to hotspot adds its IP address to one of 4 address lists in firewall
for example
user1 logs and its IP address appears on list1
user2 logs and its IP address appears on list2
user3 logs and its IP address appears on list3
user4 logs and its IP address appears on list4
user5 logs and its IP address appears on list1
user6 logs and its IP address appears on list2
and so on ..

It would suit me because this router on which the hotspot server is connected to a 4 DSL lines. I think that’s the simplest way to distribute traffic along lines.

P:S: sorry for bad english

User Manager does not have “random” feature, that allows to set random list in order you have described, it is more static value.