Since Autodesk is not a Microsoft product you won't find one among the
Microsoft newsgroups. Autodesk calls their's Communities and there are
about a dozen for the various areas of interest. Simply navigate to
Autodesk's main page above and look at the links across the top. The
rightmost one is what you want.
My newsserver lists alt.autocad and also shows numerous groups beginning
with autocad. , so I suggest you go to the Autodesk web site to find out how
to access their newsserver.