Look in the package "jabber" in the c section (contrib/packages/jabber/c). There you will find code for nsjabber which should give you some hints (albeit in C) on how to achieve what you want within the AOLserver.
Sadly this is not for beginners, so unless you know C and something about socket programming and threading, it might not be of much use to look at this.
Last but not least, this code was written by Björn Kiesbye, so you might want to contact him directly if you have questions.
