I'm fairly familiar with CAXL, and I don't think there's any way to do that. You'd probably be able to view a stored transcript if you set up your CIMP server to archive all messages.
EDITED TO ADD: David Staudt had a good idea. If both participants are using the web app, you could write the web app to copy automatically all messages to a third client when they are sent. The third client (the person monitoring) would get all messages in the conversation. The people chatting wouldn't know that their messages are being forwarded to the third client unless you told them.
You could even write it so that the messages to the third client include identifications such as "Msg from joe@hisdomain.com to debby@herdomain.com: How are you today?" That way you can see who is talking to whom.