There are two segments to go to the Conference Venue in Banff, Canada:

1.Take flights from anywhere in the world to Calgary International Airport

2.Travel from Calgary International Airport to Banff National Park

1. Take flights from anywhere in the world to Calgary International Airport

The final destination is Calgary (YYC), actually, Calgary is a very large
international airport in Canada. However, if you can not find a directly flight to
Calgary International Airport, first of all, you can take flight any major cities in
Canada, for examples, Vancouver (YVR), Toronto (YYZ), or Montreal (YUL).
And then transfer from these airports to Calgary (YYC).

2. Travel from Calgary International Airport to Banff National Park

Second, you may need to rent a car and drive to Banff National Park or
book a shuttle bus for the trip. 

You can find the information for both of the two ways from the website of
conference venue:

http://www.banffparklodge.com/utility/how_to_get_here.html#book