How to setup Instant Messaging using WebEx Connect / RTC (XMPP protocol)

Hi,

I'd like to set up instant messaging in RTC (with no success far).

The company uses WebEx Connect as its IM service. In principle, this uses the XMPP protocol

I am able to connect to the IM server using other XMPP clients, e.g., Pidgin (following the instructions posted here).

However, when setting up an associated XMPP connection in RTC, the only result I get is an error message:

Error running operation 'Connect to Collaboration Services'

Not connected to server.
Not connected to server.

Has anyone been able to successfully setup a WebEx Connect / XMPP / RTC  integration? If so, any hint how to achieve it is greatly appreciated.

Thanks & cheers
Timo.