Knob control anyone?

Has anyone out there created a Knob control class? The kind often used in music software to represent rotary knobs,
with an indicator to show the current value, mouse input to set the value, etc.

I thought this would be useful and assumed that there would be code around, but I can't find anything anywhere.
Mabry make an ActiveX knob control (www.mabry.com), and so do NED (Northeast Data Corp), but I really want
to be able to program my own (preferably based on someone else's fine work of course).

Anybody done this before, or got any ideas on how to build one?

I usually don't respond to anonymous postings but I decided to this time.
Check out the MSDN sample FWTEST. I has a knob in it. This is fairly
old code and might require cleaning up. By the way, I see this question
about once per month on average so if you can make a generic knob and
would like to write an article and submit it to this site I am sure you will
find a grateful and receptive audience.