What version of mbox are you using? If you using mbox.js you can override your IP address with an IP address from a different location and use the mboxOverride.browserIP url parameter. So if your company is in the UK, but your global campaign targets visitors in Aukland, New Zealand, use this style of URL assuming that 60.234.0.36 is an IP address in Auckland: to over http://www.mycompany.com?boxOverride.browserIp=60.234.0.36
If you are using at.js, you can use the QA link to view the experience.