using System;
using System.IO;
using System.Text.RegularExpressions;
 
public class Test
{
	public static void Main()
	{
		var s = "'This is not captured' but this is and not or empty() notempty() currentdate() capture";
		var rx = new Regex(@"(?:'[^']*'|(?:\b(?:(?:not)?empty|currentdate)\(\)|and|or|not))|([!@#$%^&*_.\w-]+)");
		Console.WriteLine(rx.Replace(s, repl));
	}
	public static string repl(Match m)
	{
		return !string.IsNullOrEmpty(m.Groups[1].Value) ? m.Value.Replace(m.Groups[1].Value, string.Format("'{0}'", m.Groups[1].Value)) : m.Value;
	}
}

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