I've only recently started looking at AutoCad again.
There used to be an arx file written by Jorge?? in Autodesk which allowed
you to dock your toolbars. - accont.arx.
The date I have is 01/04/2000
It was a little difficult to use as I remember and in the end I gave it up.
My toolbar ended up independant of AutoCAD, but followed it around.