Mass spectra for successful drawing

Hello,
I need a macro for solve a mass spectroscopy problem (mass spectrum). I have columns A and B (m/z numbers and abudances). How to fill column C with numbers from (by example) 25 to maximum obtained from A (=7) which is realy 450 and copy appropriate values from B in D? In separate sheet I have rows C and D, how to delete rows with zeroes (0) in D?

A B C D
1 a1 1 a1
2 a2 2 a2
4 a3 3 0
5 a4 4 a3
7 a5 5 a4
6 0
7 a5

In spe.