Excel 2010: Index, Match and Continue Subtract Values until - Microsoft Community

i have data below need compare 2 columns (a , c), find exact match using columns , c (i.e. "string") , when matches found take string1 value (column b) , continue subtract string (column d) until matches found (that example, string1 "b1-d1, b1-d2, b1-d3"). further in case if (b1=d1) should called "false".

any calculation match appreciated dealing 5000 entries find if (b1=d1, b1>d1 or b1<d1).

a         b       c         d             string1   500    string1    300  string2   1000   string1    400  string3   1500   string1    600                   string2    750                   string2    845                   string2    1350                   string3    1200                   string3    1400                   string3    1700                    string3    1775   

***changed office product moderator***

(that example, string1 "b1-d1, b1-d2, b1-d3").

further in case if (b1=d1) should called "false".

i'm not sure mean "called false", see formula g1.

f1:  =b1-sumif($c$1:$c$5000,a1,$d$1:$d$5000)
g1:  {=iferror(match(a1&b1,$c$1:$c$5000&$d$1:$d$5000,0)>0,false())}

drag formulas down till have data in column a:b

andreas.

Office / Excel / Windows other / Office 2010