Actually for anyone trying to implement this on the trial, i found a workaround.
You have to setup a SIP Trunk, with incoming calls only, with your 3CX's public IP (not the IP you are connecting from), and set the main no. to just a number you will be calling to (e.g. 1001).
After setting up inbound routes with DIDs, you can make a call to 1001@<your domain>:5060 and it will be redirected to your system.