cropping an Excel shape

[wdarmes]

I am trying to use Excel 2007 to display a star-rating system in which companies are rated one star, two stars, two and one-half stars, etc. I cannot figure out how to show a one-half star. If I could crop the star shape, that would solve the problem, but I have not been able to do so -- the drawing tools for editing the shape have a crop feature, but when I select the star, this feature is deactivated. Also, I don't know if there's a way to save the star as a jpg file, which would allow me to use picture tools, which does have an active cropping feature.

Thank you.