Lens adapter to put Canon lens on Nikon D70 ?

As a rookie, I have a Canon EOS Rebel (film) camera with a
ProMaster 70-300mm lens.
I'm getting a Nikon D70. Is there an adapter that will allow
me to use the Canon ProMaster lens on my Nikon D70 body ?
If so, roughly how much $ and where to get ? And what are
the downsides (auto focus won't work ? etc ?).
I simply cannot afford another 300mm lens yet and need one to
shoot football with the D70. So even if it is not ideal to
reuse my ProMaster lens, if I can't then I can't get the D70
yet and must suffer through another football season shooting
film (very badly) with my Canon Rebel.
Thanks for any advice...

Bob