using System;
using System.Text.RegularExpressions;

public class Test
{
	public static void Main()
	{
		string input = "(src=\"cid:image001.png@01D081C1.C5908B40\")";
		string replacement = "src=\"\\\\resources\\\\images\\\\$1\"";
		Regex rgx = new Regex("src=\"cid:(image[0-9]+\\.png)@[A-Za-z0-9]+\\.[A-Za-z0-9]+\"");
		Console.WriteLine(rgx.Replace(input, replacement));
	}
}