I haven't tried this with this version of CCM, but it should work fine. It can either be done with a trunk or a gateway on the CCM side. Make sure the codec is the same on both sides or that there is a transcoder available. Also, on CCME, you will need an incoming dial peer for calls from CCM to CCME.
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...