[MlMt] keyboard command to "Jump to 'to:' field"?

[TJ Luoma]

When I create a reply, there are certain circumstances where I would
like to be able to jump right to the "To:" header (also the Subject:
line header).

I can create a Keyboard Maestro macro for this (by repeating
'shift-tab'), but it would change depending on which headers are shown
in the compose window.

I looked through the documentation and didn't see anything which
seemed to allow for this, but I thought I'd ask just in case I'd
missed it.

TjL