I suggest changing this by adding a web.config variable (possibly into the appSettings) that determines the path to the administration folder. This way one can set the Administration folder to whatever path or name without having to manually changing the source code in the CommonHelper.
/// <summary>
/// Gets store admin location
/// </summary>
/// <param name="useSsl">Use SSL</param>
/// <returns>Store admin location</returns>
public static string GetStoreAdminLocation(bool useSsl)
{
string result = GetStoreLocation(useSsl);
result += "Administration/";
return result.ToLowerInvariant();
}