Is it possible to use std::regex and std::match_results with custom string type?

I am working on a project that has a custom string type, MyString. I can match on it just fine like this:

MyString getMatch() {
  static const std::regex MyRegularExpression(R"RX(^blah=([a-z0-9]+)$)RX");
  const MyString str = "blah=25";
  std::cmatch match;
  if (std::regex_match(str.GetConstCharPtr(), match, MyRegularExpression))
  {
    return MyString(match[1].str().c_str());
  }
  else {
    return "";
  }
}

But as you can see, I have to convert from cmatchs std::string back to MyString when returning the value. It's not a big deal at all, but I noticed that std::match_results is heavily templated, so I was wondered if it's possible to somehow put MyString to its template arguments to get match results already as MyString.

Is it possible? If yes, how to do it?