How do you Sum the range of two lookup values?

[Guest]

This is my lookup function.
=LOOKUP("Next Accrual",A5:A25,C5:C25)
I need a formula that will add the range from C5 to the point where this
lookup function is satisfied.

 

[Frank Kabel]

Hi
try:
=SUM(OFFSET($C$5,0,0,MATCH("Next Accrual",A5:A25,0)))