Errata ....

I wrote:
Then I can use it in the worksheet in any of the following ways:
=myrnd()
=myrnd(A1)
=myrnd(A1:C10)

Of course, all instances of "myrnd" shoud be "myrand". I
variously use "rnd" and "rand" in the name because of the
different in spelling between Excel and VBA. "Sometimes
you feel like a nut; sometimes you don't" :-).