There may exist utilities which drill down the catalog/schema of a given server/database and use this info to search for a given match (or partial match) with a given pattern in all the text-like columns. You could possibly even write such a utility and introduce heuristics of your own (say not to search tables which have more than 10,000 rows because you expect the info to be a "configuration-type" table etc.)
An easier way may be to use SQL-Profiler to record every query sent to server (possibly filtered by IP address, by session id etc..). By then running the underlying application so that it would produce the particular string, you'll have a [hopefully] short list of queries, one of which targets the particular table / column where the path/string or parts therefore gets queried from.