I am working on small module in which we pass the column name as comma-separated string to a stored procedure. In the stored procedure, we want to separate the column names out.
The definitive article on the topic is Arrays and Lists in SQL Server 2005 and Beyond which contains code and performance test results for a variety of split functions.
You say these are column names? You should probably read another of Erland's articles on The Curse and Blessings of Dynamic SQL where he discusses both SQL injection and when dynamic SQL is a good idea.