G'day Roger.
I'd like to know if my software (ninox) could handle this... it's designed for aligning and stacking planetary images but it seems likely that it will work for comets as well...
Can you send me a set of sample frames to test? Or you can try it for yourself -
www.acquerra.com.au/astro/software/ninox
If you'd like to send me some frames, PM me for my email address.
cheers, Bird