Hi, I want to get the slope from Column C using a certain range of dates from
Column A. I did this already for getting the max value, but I do not how to
do it using Slope.

Example I did using Max:
=MAX(IF(ISNUMBER(MATCH($A$2:$A$500,M2:N2,0)),$c$2: $c$500))
M2=8/25/2009
N2=8/27/2009

"I need Slope"

ColumnA ColumnB ColumnC
8/24/2009 345 34
8/25/2009 345 465
8/25/2009 567 566
8/25/2009 456 465
8/26/2009 456 876
8/26/2009 244 243
8/26/2009 123 264
8/26/2009 876 436
8/27/2009 678 134
8/27/2009 484 134
8/27/2009 356 654
8/27/2009 456 456
8/27/2009 234 123
8/28/2009 567 453