i want to know whether a string is in a cell, built-in search function,
using formula of vlookup and find do not help.

e.g. i'm searching the word "now"

the text "i want to know whether a string is in a cell, built-in search
function, using formula of vlookup and find do not help." will be returned
as a match while it is not i want.

could anybody tell me what i can do? thanks in advance.