a chat hack for

ok lets say i got a service called digi chat installed on my server is it possable to make a hack that will <after clicking a link in board> log the person into the digichat
digichat has a place to login on a html page and digi chat is a java applet chat it goes to the html page and loads a little applet then ya type ur name ina box and connect hopefully soemone can write this thing maybe it isnt a hack maybe soemthing else but i put it here if you need to see a digichat html page please feel free to mail me and i will link you to my chat page thanx