If you're talking fuzzy string comparison, this is an amount of risk that the result could be false. Some function like VLOOKUP allow approximation, but I've never tried that on text.
VBA can offer a solution, but you'd need to build your own string comparison or adapt another person's solution to your situation, such as in this post:
http://www.mrexcel.com/pc07.shtml
I've seen others that have kept a repository table that the value is checked against. If the value exists, the second column has a default value for that person/client/company/etc. If the value doesn't exist, the user adds it to the list along with a default value for reference next time.