i got alot of columns in a sheet and i want to use the sumproduct to calculate

the sum of a vehicle no based on a few criterias(e.g) =sumproduct(--

(a1:a100="A"),--(b1:b100="b"),--( the problem lies here), K1:k100).

In "the problem lies here" criteria, the column (C1:c100) is description on the

parts purchased . but what i want to sum is those entries that has the

words "To replace" in front of the entire description. The description can be like:

To replace tyre no 5

It is better to use substitute, replace or left or all of them ? pls advise . thank u