From my limited experience, you can only fly standby from the original ticketed location or a co-terminal. You'll also still have to make a connection.

As for the connection, until last week, I thought you had to keep the original routing including the same connecting city. However, I was allowed to standby out of a co-terminal through a different connecting city. Not sure if this is policy or I had a generous ticketing agent.

Your fare rules can have an impact on what you can do. I called into the Plat desk and, after reviewing the fare rules, they walked me through all of the alternatives including flying out of a co-terminal.

Best bet for you might be calling the EXP desk and let them do some of the legwork for you.