Welcome to Flyertalk 93732, welcome to the BA forum too, and feel free to revert with any followup questions. Alaska flights need a telephone call, and the process is what you've done really: find it on AA.com then ring BAEC.

There are a number of stickies up the top of the forum, plus the Dashboard, that may help you find out the basic facts. One key one being the limitations of BA.com which many of us have to work around. One of my favourite threads in this area, though it is now a little dated, is this one, just the first few posts:
http://www.flyertalk.com/forum/briti...tart-here.html