KMP supports external detection of an IP address. The way this works is that KMP requests a page from the URL specified, and then parses the resultant page, looking for the IP address. It considers anything after the first occurrence of the "preceding string" and before the next occurrence of the "following string" to be the IP address.
Here is a sample ASP file that could be run on an external Microsoft IIS server to provide KMP with the address it needs.
<html>
<body>
Your IP address is "<%=Request.ServerVariables("REMOTE_ADDR")%>"
</body>
</html>
The author of KMP can provide an external address detection service, but the service, unlike KMP itself, does not come for free. If you are interested, please contact the author.
Note:
An example of a service that provides the address externally is http://www.whatismyip.com. For this service, at the time of this publication the "Preceding String" would be "<h1>Your IP is " (without the quotes), and the "Following String" would be "<br></h1>".
Another example, valid at the time of this publication, is http://checkip.dyndns.org, where the "Preceding String" would be "Current IP Address: " and the "Following String" would be "</body>".