Adelboden is over 3 hours away from Geneva, by public transport, but it's not too difficult to get to:
Here's a typical journey plan from Geneva to Adelboden (based upon the timetables which apply tomorrow morning):
Take 0810 from Geneva to Bern. Arrives 0956.
Then take the 1006 train to Frutigen. Arrives 1049.
Catch bus number 10, from outside Frutigen station, to Adelboden post office. Departs 1054. Arrives 1124.
Total journey time = 3 hours 14 minutes.
(All you'd then have to do would be to find a taxi to take you to the specific address).
Information about Adelboden is here:
http://www.adelboden.ch/en/welcome.cfm
Journey planning can be done on the Swiss Railways website (which is in English and includes the bus connections):
http://www.sbb.ch/en/index.htm
Chris