using System;
using System.Text.RegularExpressions;
public class Test
{
public static void Main()
{
string txt = "~A.~ ( tilde, then any single upper case letter, then dot, then tilde)";
string pattern = "~([A-Z])\\.~";
string replacement = "~$1\u2006~";
Regex rx = new Regex(pattern);
string result = rx.Replace(txt, replacement);
Console.WriteLine("Replacement String: {0}", result);
}
}
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