We use Call Manager 4.2(3). We have about 90 phones already deployed with two lines and the other four are for speed dials. For one of the lines reserved for a speed dial, we'd like to add the speed dial number. Can this be done via BAT for existing phones? I'm sure I can do it if I were adding new phones. I haven't spent enough time with it yet...only glanced at it so far.
Sadly this is one thing cannot be changed via the BAT Tool. You are most correct that it can be done when adding new phones. You could however do an Export (all details) from BAT. Change the Template to add the specified Speed Dial and then re-Import the sets.
Try a few practice runs or test phones first to perfect the process.