There is one problem with your script: it will not find all instances of the text in SPs, Views or functions that are larger then 4000 characters and the searchabe text is close to the 4000 character position. Because SQL Server will split the code between multiple syscomments records you may end up with 'Joshua' in one syscomments record and 'A Walker' in another.

In order to prevent this you could use something similar

SELECT DISTINCT name

FROM syscomments SC

INNER JOIN sysobjects SO ON SC.id = SO.id

WHERE SC.text LIKE '%' + @FieldName + '%'

UNION

SELECT DISTINCT name

FROM syscomments AS L1

INNER JOIN sysobjects SO ON L1.id = SO.id

INNER JOIN syscomments AS L2 ON L1.id = L2.id

AND L1.colid = L2.colid - 1

WHERE RIGHT(L1.text, 50) + LEFT(L2.text, 50) LIKE '%' + @FieldName + '%'

This is what I use when looking for a text in the SQL code. It only works for one database but so far I did not have a need to search all databases on a server.