Open Stack

Its very weird requirement, stay with me to explain.

We have /24 public IP pool which we are using since long time and we
cherry picked IP address from that pool so they are not in sequence :(

Now we have openstack and i want to give some floating IP to openstack
but because of non-sequence range how do i give individual IP address
to floating pool in VLAN?

In single VLAN 10 net how do i put individual IP in subnet?