Can i Setup userman to watch usage from just IP's ??

Hi,


What i am trying / hoping to do is to be able to link up certain IPS to certain Userman Users and then it must watch and count the traffic that they use?


Reason why i want to do it is cause i have 2 or 3 Clients that user PPPoE and they are all sererate from each other but now i have 3 companies that are all independant but they want to be conencted to each other (on tghe same network) so i need to give each company their own bill each month with out having to isolate them



So like
IP:

192.168.0.50 -192.168.0.70 links to user4 on userman

and

192.168.0.71 -192.168.0.90 links to user5 on userman

and

192.168.0.90 -192.168.0.110 links to user6 on userman


???