from Hakodate to Niseko

How can I get to Niseko Rusutsu Resort from Hakodate? By train, do I need to transfer? Is there any direct bus?

Niseko and Rusutsu are two separate towns!

Niseko:
http://www.japan-guide.com/e/e6720.html

Rusutsu:
http://www.japan-guide.com/e/e6715.html

yes,I know. I'm goint to Sapporo, move to Hakodate and then to Niseko. I know I can ride JR express from Sapporo to Hakodate but I'm not sure from Hakodate to Niseko. Is there any inter city bus between them? is it better than the train?

The best way by public transportation from Hakodate to Niseko is by train via Oshamanbe. Depending on your final destination within Niseko, get off at either Niseko or Kutchan Station:
http://www.jorudan.co.jp/english/norikae/

Access from Hakodate to Rusutsu is more complicated.

Oh, dear... I've reserved the Rusutsu!! I' better rent a car from Hakodate then. Thanks...

I believe there is a bus from Kutchan Station to Rusutsu. Or from Lake Toya Onen to Rusutsu. Lake Toya can be reached in a short bus ride from JR Toya Station.