There are lots of posts suggesting you can't do this but it seems to work fine in 2012.

EG:

USE IMPORT;

-- CREATE FULLTEXT CATALOG ft AS DEFAULT;

DROP TABLE test;

CREATE TABLE test (ID int not null,string varchar(max));

INSERT INTO test VALUES (1,'this is a bit of text with the term C# somewhere in it'),(2,'and this one uses C++ instead.'),(3,'whilst this just has a c in it somewhere')

CREATE UNIQUE INDEX ixID ON test (ID);

CREATE FULLTEXT INDEX ON test (string) KEY INDEX ixID;

SELECT * FROM test WHERE CONTAINS(string,'C#');

SELECT * FROM test WHERE CHARINDEX('C#',string)>0;

Returns:

ID string

1this is a bit of text with the term C# somewhere in it

ID string

1this is a bit of text with the term C# somewhere in it

However (BIG however).....

If you change the above script and replace all instances of C# with, say, X# and all instances of C++ with X++ then you'll find that it doesn't work any more. What this means is that Microsoft must have a list of "words" that full text indexing is able to pick up on: if your search terms, as in the OP, are included in that list then you're fine, but if they are not then you're no further forward. Someone with more experience of full text editting can probably tell you if and how you might control the "word list"........