.Net regular expression replace - prepend each word with certain character

Input "col1, col2, col3, coln"

Output "@col1, @col2, @col3, @coln"

Try this:

string input = "col1, col2, col3, coln";
string pattern = @"\b(\w+)\b";
string result = Regex.Replace(input, pattern, "@$1");
Console.WriteLine(result);

string input = "col1, col2, col3, coln";
string result = "@" + Regex.Replace(input, @"\s+", " @");

It depends how robust you want it to be, of course. But if it's just for SQL query parameters, which is what it appears to be, then the above should be fine.