ExcelBanter - VLOOKUP + Something

I have a 40 year Capital Item Replacement Program.
This formula is in Row 4 , Columns B thru AP
=if(ISNA(VLOOKUP(H2,Sheet7!$C$19:$C$D28,2,False)), 0,VLOOKUP(H2,Sheet7!$C$19:$D$28,2,False))
Row 2, Column B thru AP =2002 to 2042. Therefore B2=2002 & H2 = 2008 etc.
The number in the reference cells on Page 7 is variable depending on a
number input into another cell on Page 7.
For instance an article installed in 1995 to be replaced in 13 years would
be replaced in 2008. So far it works and puts a number in cell H4.
My question, how do I get it to put a number in the 26th & 39th year?
Any help appreciated.
Thank You -- Duane Platt