using System.Text.RegularExpressions;
public static void Main()
string uri = @"Selection=(AreaId%3d*%27S0304%27%26PersonId%3d%27197803140412%27)&Selection=(AreaId%3D*'S0304')&SelectionPanelVisible=True&SelectionSubmitted=true";
var regex = new Regex(Regex.Escape(@"Selection=(AreaId%3d*%27S0304%27%26PersonId%3d%27197803140412%27)"));
uri = regex.Replace(uri, string.Empty, 1);