Sorry, I forgot about the "even rows" condition. Try it this way...

Over 15
=========
=SUMPRODUCT((MOD(ROW(A:A),2)=0)*(A:A15))

Between 14 and 15
===================
=SUMPRODUCT((MOD(ROW(A:A),2)=0)*(A:A=14)*(A:A<= 15))

These require Excel 2007. Excel 2003 and prior choke on entire column
references in array formulas.

FWIW, the between 14 and 15 formula on A3:A102 could be calculated
using

=SUMPRODUCT(MOD(ROW(A3:A102)-1,2)*(ABS(A3:A102-14.5)<=0.5))

The OP said he was using XL2007 in the first line of his post.

--
Rick (MVP - Excel)