using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = "--(.+?)--";
string replacement = "($1)";
string input = "He said--decisively--that the time--whatever time it was--had come.";
foreach (Match match in Regex.Matches(input, pattern))
{
string result = match.Result(replacement);
Console.WriteLine(result);
}
}
}