How to add Eye of the North key to Guild Wars?

I recently purchase the Guild Wars Trilogy via Steam. To complete my collection, I purchased Eye of the North via Amazon (because it was cheaper there than through the store). Only problem is I can't figure out how to add the key to my account.

According to the access key card I have, the key is in the format of XXX-XXXX-XXXX

When I go to add the key to my account, I am only able to add a key in the format of:

XXXX-XXXX-XXXX-XXXX-XXXX

It doesn't accept the format that my key came in.

Can someone tell me how to add the game to my account? Thanks!

Is your card perforated along the edges? If so, tear it open, the real key is inside.

Ah-ha! Thanks! I actually just thought of that.

If I had a dollar for every time this has happened...