Setting Listening Port

[toofewacres]

Is there a way to set the listening port to a preset value? I use a VPN and the forwarded port number changes hourly (I know it sounds dumb...). I can "capture" this new port number value but would like to add it to BitTorrent automatically.

 

Is there a way thru the WebAPI? Is there any other documentation for the WebAPI? I can't seem to get the web page to the the current settings (?action=getsettings) If there is a value for listening port that I can put into a json file and read in that might be my solution...