Host and Guest - 2 external IP's

Hi all,

At the moment I have a server that has an external IP address on it, and the datacenter has given me another IP for it. The host OS is Windows 2012 R2 Datacenter. 

I also want to have another Server 2k12 R2 guest running on it. However, I want to use IP1 on the host and IP2 on the guest. All the times I have done this before it hasnt worked. Does anyone have any documentation to do this? Is it a case that I don't configure the 2nd IP on the host and just assign it to the guest (through the public switch). All the times that I have done this before, it has been a case of either the host or the guest has external access, and not both at the same time, which is what I want. 

Is this possible, if so, How do I do it?

Thanks

Harry