GeoIP Database

Web Proxy Checker Pro allows to detect countries of proxies - on Advanced tab check "Detect proxy country" and enter the path to "IP2Country database".

Format of IP2Country database is:

ip1,ip2,country_code

where ip1 and ip2 are numbers, country_code is 2-character country code.

You can download IP2Country database from www.maxmind.com (GeoLite Country CSV Format). To convert the maxmind csv file to the proper format, described above, you can use RegExp Extractor.