Works only part of the time?

I am trying to code an IRC bot and am having a few problems. The bot will record chatter in a channel and log it along with the user's nickname and handle. A user's "handle" is how they are recognized on GamesNET with SrvX (completely unrelated to my bot). I want to try to capture their handle and record it every time a user joins a channel. There are two ways of doing this:
a) the user has set mode +x on themselves. This means their hostmask is something like nick!ident@handle.user.gamesnet. I can then, obviously, pull their handle from that.
b) another way which isn't important to this post.

Anyway, the necessary information is that when a user joins a channel, the bot gets their whole hostmask. The hostmask is displayed in the form of (for example):
scr0llwheel!scr0ll@scr0llwheel.user.gamesnet

I want to get the 2nd "scr0llwheel" from that string (scr0llwheel!scr0ll@scr0llwheel.user.gamesnet)

Right now, I have...

Code:

void CBot::OnJoin(string strUsername, string strChannel)
{
   string strHandle, strHandle2, strGamesnet;
   strGamesnet = strUsername.substr(strUsername.find_first_of('.') + 6);
   if (strGamesnet == "gamesnet ") {
      strHandle = strUsername.substr(strUsername.find_first_of('@') + 1);
      strHandle2 = strHandle.substr(0,strHandle.find_first_of('.'));
      PrivMsg(strChannel, "handle: " + strHandle2);
   }
}

The problem is: it works, but only some of the time?! I *think* it might have something to do with IRC, not my code but I wanted to post the code here in hopes of someone pointing out a problem, how to improve it, etc.

As you can probably tell, I'm new to programming C/C++ so any help would be greatly appreciated.

Thanks,
scr0llwheel

Originally posted by scr0llwheel

Code:

strGamesnet = strUsername.substr(strUsername.find_first_of('.') + 6);

There probably can be periods prior to the ".user." Check for the LAST period and just add 1 instead of finding the first period and adding 6.

strGamesnet = strUsername.substr(strUsername.find_last_of('.') + 1);