Saw this and your comments on IRC once I got back to my computer. I think that using named answers and a javaScript (which you can insert using HEADER_TXT() ) would be one way to set the tab order.
For other's reference here is the url which you found:
we could also modify ANS_RULE and associated macros so that it
accepted an optional hash or hash reference
which would allow us to add arbitrary tags
to any ANS_RULE (use the key/value pairs in the hash to
place key/value pairs in the HTML mark up). I haven't tested this
but I think it would allow you to add tabIndex=>"3" type attribute tags.
It wouldn't get in the way of existing usage. This would solve your current problem, do you think it would be a good idea in general?
-- Mike