A regular expression would be perfect to isolate the second result:
#include <regex>
std::regex r("^Address:\s+((?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.|$)){4})$");
std::smatch match;
std::string address;
if (std::regex_match(result, match, r))
{
address = match[match.size() > 1 ? 1 : 0]; }