excel help

[HOMMER]

I have a sum of numbers that i total over different cells. I a different cell I type a number say 500. I want a formula that will find when that number 500 reaches but does not go over. then display the contents os the cell two below it.

a5=100
a10=200
a15=100
a20=101
a25=50
ok the 500 is reached at cell a20 I want to display the contents of cell a18. This number(500) is a number i type in and can change at any time.
if I type the number 550 the number is reached at cell a25 and will display the contents of cell a23.
I sum numbers all over the work sheet not just in the a coloumn.
please help

 

[JVFriederick]

This looks similar to the Products Track posting on June 4.

I sent an email tonight with a file that I think should work.