Hi all,
after extensive googling I have found that in the good old days observatories used to use a Bifilar Micrometer which was calibrated to the relative motion of the comet to track it.
It involved hand-guiding on a nearby star as well as periodically adjusting the Micrometer to adjust for the comet's motion :S
Sounds like a guide scope and guiding on the nucleous is the easiest way to go..
