Find 2 lowest point to form a trendline

Dear expert,

Cell AH67:AH77 contain a series of data.
Actaully, they are the results from an array of formula.
Sometimes, it has 12 data. Sometimes, the data series has 8 data like this
case.
The question is that ...
I would like to find 2 lowest point so that I can draw a line to form like a
trendline (using slope, intercept).
=Small(AH67:AH77,1)
=Small(AH67:AH77,2) can help .... BUT ...

I need the ist and 2nd latest point only.
In this case, it should select 18.25 and 24.59
Although 21.36 in 22 Jan is lower than 24.59, but line is drawn forward (not
backward).
Lowest point is easy to find, how about the 2 lowest point which must come
after the lowest point.
If lowest point is the latest, it can give "no line".

21.36 22-Jan-10
35.04 28-Jan-10
36.34 02-Feb-10
18.25 09-Feb-10
57.50 19-Feb-10
67.52 02-Mar-10
26.85 18-Mar-10
24.59 01-Apr-10