I also have the same problem.
I have been using a piZero with a home brew station and would like to be able to add extra sensors using the datain38.ini file, but my las attempt at asking this question had no reply http://discourse.weather-watch.com/p/493234
I have been running this station since Oct 2016 with no problems, would like to add extra sensors, but how? as a minimum would like another sensor for Temp/Hum in the Pollytunnel.