find a particular value in the table

I've looked at fnFilter and while it works it does not do what I need.
Basically I want to find out if a particular row exists in the table and if it does not I want to add the row, preferably without going through the entire table. I know what column I want to check against.
I guess I'm looking for something like fnFindRow(column to search in, search value to look for)

While fnFilter works fine, I don't want to see the results of the filtering, I just want to know if the row already exists.

Any chance?