http://www.renderosity.com/mod/forumpro/showthread.php?unignore=15858&thread_id=2755438

here's a thread on it from 2008.

Rigging really doesn't make sense for a cape, but if you want to do that to yourself, the thread above might help. 

the easiest way would likely be to smart-prop parent it to the figure - neck or chest most likely - and then create pose morphs, which you could do via the cloth room and wind generator, magnets, etc. 

You can also create pose handles, much like how dresses and robes are sometimes done. Unfortunately I don't make dresses, I make clothes that guys wear, so I'm not too familiar with the ins-n-outs of that just yet. I do know it can be tricky.

 

~Shane