I would think there is a way to do what you are asking and the software would document it. You could probably write a script and add it to the /etc/rc.d/rclocal file. That would execute after all the init scripts during boot and get your 24online client started.
Here is another option. There is a project called linc on Sourceforge that may solve your problem. This client uses a configuration file to store your password and other login information. The client is a daemon process that can be started up when your system boots. Here is the
linc homepage and their
project page.
If I get some time I may try to write something that simulates what you are trying to do.
Bill