You can add an entry to your hosts file. I would recommend using something other than localhost if possible because I don't know what this will do to your system. You'll be trying this at your own risk I'm afraid.
For Windows, open notepad and open C:\windows\system32\drivers\etc\hosts. In there change the ip address of localhost to that of your OS X machine (If you're not on XP you'll need to run the command prompt elevated).
Then you should be able to run ipconfig /flushdns and give it a go in IE.
An alternative method (as your target is OS X) is to use some form of SSH and port forwarding. If you enable SSH access on your OS X box, and then run PuTTY on your Windows box there is an option to forward the port while you have a connection open. The source port wants to be 80 and then fill in the address of your OSX box below that and hit Add.