Making a transparent object

Hi again

You were all so helpful before suggesting ways to make a circle, thanks.

I have another little problem, which for some  reason I cant find the  answer to.

I am making a clock face, I have an out side circle which initally is black, then I have put a smaller circle on top of the lager one, and using the powerclip feature I can place photos etc on the inside area.

What I want to do is make that outside, currently black area, transparent, or at least nearly totally transparent.  I want that outer ring to show through the parts of the photo underneath to be out of focus or blurred what ever the proper term.  I need it to be virtually transparent so that I am able to place black numbers over the top to indicate the time.  To be able to give that virtually outer ring a colour tint would be great as well.

Any suggestions, I hope I have described what I want clearly.

Thanks for looking

Kind regards

Phil Allen