using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        var input = "select id, :DATA_INI, ':DATA_INI', titulo, date_format(data_criacao,'%d/%m/%Y %H:%i') str_data_criacao" + System.Environment.NewLine +

                    "from v$sugestoes" + System.Environment.NewLine +

                    "where data_criacao between :DATA_INI AND :DATA_FIM" + System.Environment.NewLine +

                    "order by data_criacao";

        Console.WriteLine(Regex.Replace(input, @"(?<!'):(\w+)", "@$1"));

    }

}