Hi,
CVI does not have native multiple IP support, the GetTCPHostAddress function will ask the OS for a list of the IP addresses available and it will return the first one reported by the OS. I've dome some testing here and seems that CVI will report the lower numeric value address.
You may want to look in the Windows SDK for a function that would allow you to get all the IP addresses found in the computer.
You can file a request for this feature, just go to www.ni.com/contact and select product feedback. The more request the better!
Let me know if you have other questions.
Regards,
Juan Carlos
N.I.