Any suggestions on the best way to get from Venice to Alpine Retreat of Berner Oberland?
Where in the Berner Oberland? That makes a bit of difference. If you mean this particular Alpine retreat, a chalet in Adelboden: http://www.adelboden.co.uk/ then your best route is Venice to Milan, Milan to Brig, change to the local train to Kandersteg or Frutigen and Postbus from there. If you mean the general concept of an alpine retreat and are heading to the Lauterbrunnen Valley, there are a couple of train routes that work, depending on your wishes and time to spend on the way.In any case, the "best way" is by train, as the closes you can fly is Zurich and you would still have several hours of travel from there.