Office Excel 2007

Is there a way to find the average of column of figures EXCLUDING any row
that has a zero in it?

I have a column of figures. Each row corresponds to a day, and each day a
new row is added. Some rows have a zero value entered, while the others have
a non-zero number.

Finding the average of the entire row is, I know, easy. =AVERAGE(A1:A100),
for example. However, is there an easy way to exclude cells within the
A1:A100 range that have a zero, so that the I get the sum of the non-zero
rows, divided by the number of rows with non-zero entries?

Many thanks.

Ken Isaacson
SILENT COUNSEL, a legal thriller
www.KenIsaacson.com