host multiple sites in extra ips - non main ip

I have a dedicated server with 4 ips (ip1..ip4)... and 10 sites (SX1..SX10)

i want to host multiple sites in other ips that are not the main ip

i see on the CWP the main ip is only the shared ip where i can host multilple sites, because when i add a new site (SXn) and I select another ip distinct to the main ip, the ip automatically is converted in a dedicated ip

I want the 4 ips could host multiple sites, i mean all the ips be shared to be possible the following:
ip1 (SX1, SX3, SX10)
ip2 (SX2, SX9)
ip3 (SX4, SX8)
ip4 (SX6, SX7)

how can i do this?

when creating account you can select ip, you can user for each site any ip from the servers...this is not limited to single server

when creating new account, the shared IP will be shown but please change to the IP you want to use.

the problem is only one ip (main ip) is the shared ip, if i select one of the other ips they are convert in a dedicated ip for the new site and that ip coult not be selected for more new sites