couldn't you calculate that using just B2 and C2?
=CEILING(B2/C2,1)+1
As per my comment in Chris' answer - updated version
=INDEX($A:$A,MATCH(TRUE,INDEX($B:$B<=0,0),0))
This should avoid the problem inherent in Chris' suggestion in that you get the wrong value when the first value <=0 is 0 itself.
The part $B:$B<0
returns an "array" of TRUE/FALSE
values, the first TRUE
obviously co-inciding with the first column B value <0, MATCH then finds the position of that first instance and INDEX then gets the corresponding value from column A.
The second INDEX is only there to avoid "array entry" - it works without that, i.e.
=INDEX($A:$A,MATCH(TRUE,$B:$B<=0,0))
.......but that version would need to be "array entered" - i.e. confirmed with CTRL+SHIFT+ENTER
.
It's a little more inefficient than the previous suggestions, using the whole column (and that doesn't work in Excel 2003 or earlier - in those versions you need to use a specific range).
Note that MATCH with "match type" of -1 as per Chris' suggestion needs to have descending values in column B - this formula works however column B is ordered.